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Question 178531This question is from textbook
: 12.50 In the following regression, X = total assets ($ billions), Y = total revenue ($ billions), and n = 64 large banks. (a) Write the fittedregression equation. (b) State the degrees of freedom for a two- tailed test for zero slope, and use Appendix D to find the critical value at α= .05. (c) What is your conclusion about the slope? (d) Interpret the 95 percent confidence limits for the slope. (e) Verify that F = t2 for theslope. (f) In your own words, describe the fit of this regression.
R2 0.519
Std. Error 6.977
n 64
ANOVA table
Source SS df MS F p-value
Regression 3,260.0981 1 3,260.0981 66.97 1.90E-
Residual 3,018.3339 62 48.6828
Total 6,278.4320 63
Regression output confidence interval
variables coefficients std. error t (df =62) p-value 95% lower 95% upper
Intercept 6.5763 1.9254 3.416 .0011 2.7275 10.4252
X1 0.0452 0.0055 8.183 1.90E-11 0.0342 0.0563
This question is from textbook
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Question 179157: pattern question
2, 3, 5, 7, 11...
My logic:
The pattern looks like the first two #s increases by 1 (1 time), next two increases by 2 X the previous increase which was 1 and it happens 2 times, next increase is 2 X previous increase which was 2 and should happen 4 times, so the next number should be 15, then 19, then 23
Click here to see answer by Mathtut(3670) |
Question 179157: pattern question
2, 3, 5, 7, 11...
My logic:
The pattern looks like the first two #s increases by 1 (1 time), next two increases by 2 X the previous increase which was 1 and it happens 2 times, next increase is 2 X previous increase which was 2 and should happen 4 times, so the next number should be 15, then 19, then 23
Click here to see answer by Edwin McCravy(2920) |
Question 179188: BIG Corporation produces just about everything but is currently interested in the lifetimes of its batteries, hoping to obtain its share of a market boosted by the popularity of portable CD and MP3 players. To investigate its new line of Ultra batteries, BIG randomly selects 1000 Ultra batteries and finds that they have a mean lifetime of 921 hours. Suppose that this mean applies to the population of all Ultra batteries. Complete the following statements about the distribution of lifetimes of all Ultra batteries.
Suppose that the distribution is bell-shaped. If approximatly 99.7% of the lifetime lie between 654 hours and 1188 hours, then the approximate value of the standard deviation for the distribution, according to the empirical rule is ___
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Question 179176: BIG Corporation produces just about everything but is currently interested in the lifetimes of its batteries, hoping to obtain its share of a market boosted by the popularity of portable CD and MP3 players. To investigate its new line of Ultra batteries, BIG randomly selects 1000 Ultra batteries and finds that they have a mean lifetime of 921 hours. Suppose that this mean applies to the population of all Ultra batteries. Complete the following statements about the distribution of lifetimes of all Ultra batteries.
a) According to Chebyshev's theorem, at least (56% 75%, 84%, 89% which one) of the lifetimes lie within 2 standard deviations of the mean, 921 hours.
b) Suppose the distribution was bell-shaped, If approximatly 99.7% of the lifetimes lie between 654 hours and 1188 hours, then the approximate value of the standard deviation for the distribution, according to the empiral rule is __
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Question 179216This question is from textbook
: The manager of the Portland Electronics store is concerned that his suppliers have been giving him TV sets with lower than average quality. His research shows that replacement times for TV sets have a mean of 8.2 years and a standard deviation of 1.1 years (based on data from 'Getting Things Fixed,' Consumer Reports). He then randomly selects 50 TV sets sold in the past and finds that the mean replacement time is 7.8 years.
a. Assuming that TV replacement times have a mean of 8.2 years and a standard deviation of 1.1 years, find the probability that 50 randomly selected TV sets will have a mean replacement time of 7.8 years or less.
b. Based on the result from part (a), does it appear that the Portland Electronics store has been given TV sets with lower than average quality?
This question is from textbook
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Question 179239:
Chebyshev's theorem and the empirical rule
A nationwide test taken by high school sophomores and juniors has three sections, each scored on a scale of 20 to 80. In a recent year, the national mean score for the writing section was 47.8. Based on this information, complete the following statements about the distribution of the scores on the writing section for the recent year.
a) according to chebyshevs theorem, at least (56%, 75%, 84%, 89% pick one) of the scores lie within 1.5 standard deviations of the mean 47.8
b) Suppose that the distribution is bell-shapped. If approximatly 95% of the scores lie between 28.4 and 67.2, then the approximate value of the standard deviation for the distribution, according to the empirical rule is __
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Question 179247: There is some evidence that, in the years 1981-85 , a simple name change resulted in a short-term increase in the price of certain business firms' stocks (relative to the prices of similar stocks). (See D. Horsky and P. Swyngedouw, "Does it pay to change your company's name? A stock market perspective," Marketing Science v.6, pp.320-35,1987.)
Suppose that, to test the profitability of name changes in the more recent market (the past five years), we analyze the stock prices of a large sample of corporations shortly after they changed names, and we find that the mean relative increase in stock price was about 0.88%. Suppose that this mean applies to the population of all companies that changed names during the past five years. Complete the following statements about the distribution of relative increases in stock price for all companies that changed names during the past five years.
a) According to Chebyshev's theorem, at least )56%,75%,84%,89% which one)of the relative increases on stock price lie within 2.5 standard deviations of the mean, 0.88%
b)Suppose that the distribution is bell-shaped. If approximatly 68% of the relative increases in stock price lie between 0.71% and 1.05%, then the approximate value of the standard deviation for the distribution, according to the empirical rule is__
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Question 179243: When a 1/2 liter bottle of a liquid drink is supposed to contain a mean of 520 ml and it has a known process standard deviation of 4 ml, which sampling distribution would be used if random samples of 10 bottles are to be weighed? and Why? How do I set up a hypothesis and a two-tailed decision rule for the correct mean using the 5% level of signifance? Also when the sample of 16 bottles shows a mean fill of 515 ml does this contradict the hypothesis that the true mean is 520 ml? #952
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Question 179268: a financial planner wants to compare the yield of income and growth oriented mutual funds. Fifty thousand dollars is invested in each of a sample of 35 income oriented and 40 growth oriented funds. The mean increase for a two- year period for the income fund is $1100. For the growth oriented funds the mean increase is $1090. At the 0.01 significance level is there a difference in the mean yield of the two funds? Assume that the standard deviation 1=$45 and standard deviation 2 =$55.
I have a very hard time understanding this.
We do not have a textbook for this.
I am to a. State the null and alternative hypothesis
Ho and H1
b. state the decision rule.
c. compute the value of the test statistic
d. Compute the p-value.
e. state the decision of the null hypothesis
Click here to see answer by stanbon(26259) |
Question 179255: Archie is fed up with waiting in line at his local post office and decides to take action. Over the course of the next few months, he records the waiting times for each of a random selection of 18 post office visits made by him and other customers. These waiting times (in minutes) are as follows:
27,26,13,16,8,23,22,15,16,21,11,25,30,18,12,5,10,24
construct a box-and-whisker plot for the data.
Click here to see answer by Mathtut(3670) |
Question 179346: The following data are the grades of 19 students on an algebra test..
88,56,60,93,91,55,75,79,87,76,79,90,72,94,92,75,86,72,89
construct a box-and-whisker plot for the data
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Question 179356: An experiment involves 17 participants. From these, a group of 5 participants is to be tested under a special condition. How many groups of 5 participants can be chosen, assuming that the order in which the participants are chosen is irrelevant?
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Question 179358: A certain airplane has two independent alternators to provide electrical power. The probability that a given alternator will fail on a 1-hour flight is .02. What is the probability that (a) both will fail? (b) Neither will fail? (c) One or the other will fail? Show all steps carefully.
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Question 179359: The probability is 1 in 4,000,000 that a single auto trip in the United States will result in a fatality. Over a lifetime, an average U.S. driver takes 50,000 trips. (a) What is the probability of a fatal accident over a lifetime? Explain your reasoning carefully. Hint: Assume independent events. Why might the assumption of independence be violated? (b) Why might a driver be tempted not to use a seat belt “just on this trip”?
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Question 179443: Is the mean salary of accountants who have reached partnership status higher than that for accountants who are not partners? A sample of 15 accountants who have the partnership status showed a mean salary of $82,000 with a standard deviation of $5,500. A sample of 12 $6,500. At the 0.05 significance level can we conclude that accountants at the partnership level earn larger salaries?
a. State the null and alternative hypotheses.
Ho: H1:
b. State the decision rule.
c.Compute the value of the test statistic
d. Compute the p-value.
e. What is your decision reguarding the null hypotheses?
Again there is not a book just this practice question.
Click here to see answer by stanbon(26259) |
Question 179463: A poll reported that 48% of residents opposed a new stadium. The poll was accurate to within 3%. What is the minimum percent of residents opposing the stadium?
Do I subtract 3% of 48% from 48 to find the minimum percent?
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Question 178521: Can people really identify their favorite brand of cola? Volunteers tasted Coca-Cola Classic,
Pepsi, Diet Coke, and Diet Pepsi, with the results shown below. Research question: At α = .05, is
the correctness of the prediction different for the two types of cola drinkers? Could you identify
your favorite brand in this kind of test? Since it is a 2 × 2 table, try also a two-tailed two-sample
z test for π1 = π2 (see Chapter 10) and verify that z2 is the same as your chi-square statistic. Which test do you prefer? Why? (Data are from Consumer Reports 56, no. 8 [August 1991], p. 519.)
Correct? Regular Cola Diet Cola Row Total
Yes, got it right 7 7 14
No, got it wrong 12 20 32
Col Total 19 27 46
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Question 178520: High levels of cockpit noise in an aircraft can damage the hearing of pilots who are exposed to this hazard for many hours. A Boeing 727 co-pilot collected 61 noise observations using a handheld sound meter. Noise level is defined as “Low” (under 88 decibels), “Medium” (88 to 91 decibels), or “High” (92 decibels or more). There are three flight phases (Climb, Cruise, and Descent). Research question: At α = .05, is the cockpit noise level independent of flight phase? (Data are from Capt. Robert E. Hartl, retired.) Noise
Noise Level Climb Cruise Descent Row Total
Low 6 2 6 14
Medium 18 3 8 29
High 1 3 14 18
Col Total 25 8 28 61
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Question 178519: A student team examined parked cars in four different suburban shopping malls. One hundred vehicles were examined in each location. Research question: At α = .05, does vehicle type vary by mall location? (Data are from a project by MBA students Steve Bennett, Alicia Morais, Steve Olson, and Greg Corda.) Vehic
Vehicle Type Somerset Oakland Great Lakes Jamestown Row Total
Car 44 49 36 64 193
Minivan 21 15 18 13 67
Full-sized Van 2 3 3 2 10
SUV 19 27 26 12 84
Truck 14 6 17 9 46
Col Total 100 100 100 100 400
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Question 178343: High levels of cockpit noise in an aircraft can damage the hearing of pilots who are exposed to this hazard for many hours. A Boeing 727 co-pilot collected 61 noise observations using a handheld sound meter. Noise level is defined as “Low” (under 88 decibels), “Medium” (88 to 91 decibels), or “High” (92 decibels or more). There are three flight phases (Climb, Cruise, and Descent). Research question: At α = .05, is the cockpit noise level independent of flight phase? (Data are from Capt. Robert E. Hartl, retired.) Noise
Noise Level Climb Cruise Descent Row Total
Low 6 2 6 14
Medium 18 3 8 29
High 1 3 14 18
Col Total 25 8 28 61
Click here to see answer by stanbon(26259) |
Question 177676: Sixty-four students in an introductory college economics class were asked how many credits they
had earned in college, and how certain they were about their choice of major. Research question:
At α = .01, is the degree of certainty independent of credits earned?
Earned Very Uncertain Somewhat Certain Very Certain Row Total
0–9 12 8 3 23
10–59 8 4 10 22
60 or more 1 7 11 19
Col Total 21 19 24 64
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Question 179501: Is the mean salary of accountants who have reached partnership status higher than that for accountants who are not partners? A sample of 15 accountants who have the partnership status showed a mean salary of $82,000 with a standard deviation of $5,500. A sample of 12 $6,500. At the 0.05 significance level can we conclude that accountants at the partnership level earn larger salaries?
a. State the null and alternative hypotheses.
Ho: H1:
b. State the decision rule.
c.Compute the value of the test statistic
d. Compute the p-value.
e. What is your decision reguarding the null hypotheses?
Again there is not a book just this practice question.
Click here to see answer by stanbon(26259) |
Question 176639: In a bumper test, three types of autos were deliberately crashed into a barrier at 5mph and the resulting damage in dollars was estimated. Five test vehicles of each type were crashed with results below showing. Are the mean crash DAMAGES THE SAME FOR THESE THREE VEHICLES ?
CRASH DAMAGES:
GOLIATH vARMINT WEASEL
1,600 1,290 1,090
760 1,400 2,100
880 1,390 1,830
1,950 1,850 1,250
1,220 950 1,920
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Question 179573: The following data are the numbers of local channels available in 19 cities.
11,32,32,19,5,38,17,12,37,34,16,6,11,27,7,21,15,22,18
construct a box-and-whisker plot for the data
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Question 176058: A sample of 25 concession stand purchases at the October 22 matinee of Bride of Chucky showed a mean purchase of $5.29 with a standard deviation of $3.02. For the October 26 evening showing of the same movie, for a sample of 25 purchases the mean was $5.12 with a standard deviation of $2.14. The means appear to be very close, but not the variances. At α = .05, is there a difference in variances? Show all steps clearly, including an illustration of the decision rule. (Data are from a project by statistics students Kim Dyer, Amy Pease, and Lyndsey Smith.)
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Question 172469This question is from textbook a survey of mathematics with applications
: a 10 question multiple choice exam is given, and each questions has 5 possible answers. Pascal Gonyo takes this exam and guesses at every question. use the binomial probability formula to determine the probability (to 5 decimal places) that
a. he gets exactly 2 questions correct
b. he gets no questions correct
c. he gets at least one question correct ( use information from part b)to answer this part
d. he gets at least 9 questions correct
e. without using the binomial probability formula, determine the probability that he gets exactly 2 questions correct
f. compare your answers to parts a and e. if they are not the same exaplain whyThis question is from textbook a survey of mathematics with applications
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Question 179649: In 1992, the FAA conducted 86,991 pre-employment drug tests on job applicants who were to be engaged in safety and security-related jobs, and found that 1,143 were positive. (a) Construct a 95 percent confidence interval for the population proportion of positive drug tests. (b) Why is the normality assumption not a problem, despite the very small value of p?
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Question 179654: Below are numbers of hours that a sample of 19ecent college graduates reported working last week.
42,63,43,44,39,64,51,66,58,52,53,41,50,61,45,65,54,61,60
construct a box-and-whisker plot for the data.
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Question 179742: 10.24 - 10.24 Below is a random sample of shoe sizes for 12 mothers and their daughters. (a) At α = .01, does this sample show that women’s shoe sizes have increased? State your hypotheses and show all steps clearly. (b) Is the decision close? (c) Are you convinced? (d) Why might shoe sizes change
over time? (See The Wall Street Journal, July 17, 2004.) Shoe Size 2
1 2 3 4 5 6 7 8 9 10 11 12
Daughter 8 8 7.5 8 9 9 8.5 9 9 8 7 8
Mother 7 7 7.5 8 8.5 8.5 7.5 7.5 6 8 7 7
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Question 179648: A random sample of 10 miniature Tootsie Rolls was taken from a bag. Each piece was weighed on a very accurate scale. The results in grams were
3.087 3.131 3.241 3.241 3.270 3.353 3.400 3.411 3.437 3.477
(a) Construct a 90 percent confidence interval for the true mean weight. (b) What sample size
would be necessary to estimate the true weight with an error of ± 0.03 grams with 90 percent confidence?
(c) Discuss the factors which might cause variation in the weight of Tootsie Rolls during
manufacture.
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Question 179819: Please you help me solve these problems.
How do you know, Can you write everything that you solve its?
1.) The table below shows the results of pulling one marble from a bag of marbles, recording its color, and replacing it in the bag.
-------------------------
Marble Color / Times Pulled(#)
--------------------------
Yellow..................>5
--------------------------
Red.......................>17
--------------------------
Green.....................>30
--------------------------
Find the experimental probability of each event.
1.1) Choosing a yellow marble
1.2) NOT choosing a red marble
1.3) Choosing either a red or a green marble
1.4) Which color marble is probably present in greatest number in the bag?
2.) Clarice has 7 new CDs; 3 are classical music and the rest are pop music. If she randomly grabs 3 CDs to listen to in the car on her way to school, what is the probability that she will select only classical music?
3.) Tom has a dollar's worth of dimes and dollar's worth of nickels in his pocket
a. What is the probability he will randomly select a nickel from his pocket?
b. What is the probability he will randomly select a dime from his pocket?
4.)Frank is playing darts. The results of his throws are shown in the table below. Assume that his results continue to follow this trend.
---------------------------
. Color Hit / Number of Throws .
---------------------------
Blue ....................>12
---------------------------
Red........................>5
---------------------------
White.......................>2
---------------------------
Find the experimental probability of each event.
4.1 Frank's next throw will hit white.
4.2 Frank's next throw will hit blue.
4.3 Frank's next throw will hit either red or white.
4.4 Frank's next throw will NOT hit red.
Please answer me as soon as you could, Thank you for your help.
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Question 179831: Please show me how to do these problems and please explains.
1.) A farmer has four sheepdogs and three beagles. If he randomly chooses a dog to accompany him on a walk, what is the probability of him taking a walk with sheepdog?
2.) Gordon spins a spinner with equal-sized sections numbered 1-6. In one spin, what is the likelihood that the spinner will stop on a 1 or a 5?
3.) When two number cubes labeled 1-6 are rolled, what is the probability that the result will be two 4's ?
4.) Joanne is guessing which day in November is Bess's birthday. Joanne know that Bess's birthday does not fall on an odd-numbered day. What is the probability that Joanne will guess the correct day on her first try?
Thank you for your help.
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Question 179859: A coin was flipped 60 times and came up heads 38 times. (a) At the .10 level of significance, is the coin biased toward heads? Show your decision rule and calculations.
(b) Calculate a p-value and interpret it.
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Question 179875This question is from textbook
: Sixty-four students in an introductory college economics class were asked how many credits they had earned in college, and how certain they were about their choice of major. Research question: At α = .01, is the degree of certainty independent of credits earned? Certainty
Credits Earned Very Uncertain Somewhat Certain Very Certain Row Total
0–9 12 8 3 23
10–59 8 4 10 22
60 or more 1 7 11 19
Col Total 21 19 24 64
This question is from textbook
Click here to see answer by stanbon(26259) |
Question 179923: An ordinary (fair) die is a cube with the numbers 1 through 6 on the sides (represented by painted spots). Imagine that such a die is rolled twice in succession and that the face values of the two rolls are added together. This sum is recorded as the outcome of a single trial of a random experiment.
Compute the probability of each of the following events:
Event A : The sum is greater than 6 .
Event B : The sum is an odd number.
Write your answers as exact fractions.
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Question 179944: Survey data indicate that 59% of customers at MegaHit video rental stores subscribe to premium movie channels through their cable television provider. The data also indicate that 39% of MegaHit customers own a DVD player, while 63% of MegaHit customers subscribe to premium movie channels or own a DVD player (or both). What is the probability that a randomly selected MegaHit customer both owns a DVD player and subscribes to premium movie channels?
Click here to see answer by kev82(145) |
Question 179949: A certain airplane has two independent alternators to provide electrical power. The probability that a given alternator will fail on a 1-hour is 0.2. What is probability that (a) both will fail? (b) Neither will fail? (c ) One or the other will fail? Show all steps carefully.
Click here to see answer by stanbon(26259) |
Question 180043: Suppose that 53% of all adults in a certain community are obese and that 46% suffer from diabetes. If 26% of the adults in this community are both obese and suffering from diabetes, what is the probability that a randomly chosen adult in this community is obese or suffers from diabetes (or both)?
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Question 179997: Can you solve these problem? and can you explain how to do?
1.) How many possible outcomes are there from tossing two number cubes labeled 1-6?
2.) Describe the sample space for a spinner with four equal sections of blue, red, green, and yellow.
3.) How likely is it that an outcome with a probability of 1 with occur?
4.) How likely is it that an outcome with a probability of 0 with occur?
Please answer me as soon as you could. Thank you for your help.
Click here to see answer by stanbon(26259) |
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Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860
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