Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 182175: This question was written by the professor who doesn't use books in his class.
In a package of candies, 8 candies are green, 2 are red and 6 are white. If the first candy chosen in NOT white, what is the probability that the next one will be white (assume 1st candy was NOT put back in)?
Click here to see answer by vleith(1977)   |
Question 182133: Ben rolls a 1-6 number cube. Find each probability.
1.) Ben rolls a prime number or an odd number.
Mr. Rodney's English class is made up of 28 students. He has 6 ESL students make up 1/5 of the remedial students and 3/5 of the advanced learners.
2.)What is the probability that a student is remedial and NOT ESL?
Please explain how do you know.
Please answer me as soon as you could.
Thank you for your help.
Click here to see answer by stanbon(26259) |
Question 182048: Hi can you please help me solve for this problem from book: Doane−Seward: Applied Statistics in Business and Economics, chapter 10:
Blockbuster is testing a new policy of waiving all late fees on DVD rentals using a sample of 10 randomly chosen customers. (a) At α = .10, does the data show that the mean number of monthly rentals has increased? (b) Is the decision close? (c) Are you convinced?
Customer: 1,2,3,4,5,6,7,8,9,10
No Late Fee: 14,12,14,13,10,13,12,10,13,13
Late Fee: 10,7,10,13,9,14,12,7,13,9
Thank you
Click here to see answer by stanbon(26259) |
Question 182047: Hi can you please help me solve for this problem from this book: Doane−Seward: Applied Statistics in Business and Economics,chapter 10:
A new drug is being tested to see if it reduces the number of migraine headaches. Assuming equal variances, at α = .025, do these samples of number of monthly migraines from eight volunteers who are taking the drug and eight who are not show a significant reduction in the mean number of monthly migraine headaches? (See Science News 165, no. 9 [February 28, 2004].)
Topiramate: 3 3 2 4 3 4 3 5
Control: 3 3 5 5 7 5 5 4
Thank you
Click here to see answer by stanbon(26259) |
Question 181994This question is from textbook Elementary Statistics
: Review Exercises
#16.
The average cost of a certain type of seed per acre is $42. The standard deviation is $3. Using Chebyshev's theorem, find the range in which at least 88.89% of the dte values will fall.
Please help me with this problem I understand that 1-1/k2 but i don't know who to apply it... please help me. This question is from textbook Elementary Statistics
Click here to see answer by stanbon(26259) |
Question 181991: Hi Tutors! This is one of the questions I'm stuck on. Please show me how to do it.
A traffic officer has a concealed radar unit that she uses to measure the speed of traffic crossing a bridge. She finds that the mean speed is 84km/h and the standard deviation is 5km/h.
a) What probability distribution is most likely to model the speed of the traffic crossing the bridge? Give reasons for your choice that are related to the problem and give any parameters for the distribution.
b) If the speed limit on the bridge is 90km/h, find out how many out of 200 cars she would expect to find to be breaking the limit.
Thank you very very much for your help tutors!!
Click here to see answer by stanbon(26259) |
Question 181962: Tutors, I am not understanding this problem please help:
in Business and Economics
14.16 (a) Plot the data on U.S. general aviation shipments. (b) Describe the pattern and discuss possible
causes. (c) Would a fitted trend be helpful? Explain. (d) Make a similar graph for 1992–2003 only.
Would a fitted trend be helpful in making a prediction for 2004? (e) Fit a trend model of your
choice to the 1992–2003 data. (f) Make a forecast for 2004, using either the fitted trend model or
a judgment forecast. Why is it best to ignore earlier years in this data set? Airplanes
U.S. Manufactured General Aviation Shipments, 1966–2003
Year Planes Year Planes Year Planes Year Planes
1966 15,587 1976 15,451 1986 1,495 1996 1,053
1967 13,484 1977 16,904 1987 1,085 1997 1,482
1968 13,556 1978 17,811 1988 1,143 1998 2,115
1969 12,407 1979 17,048 1989 1,535 1999 2,421
1970 7,277 1980 11,877 1990 1,134 2000 2,714
1971 7,346 1981 9,457 1991 1,021 2001 2,538
1972 9,774 1982 4,266 1992 856 2002 2,169
1973 13,646 1983 2,691 1993 870 2003 2,090
1974 14,166 1984 2,431 1994 881
1975 14,056 1985 2,029 1995 1,028
Source: U.S. Manufactured General Aviation Shipments, Statistical Databook 2003, General Aviation Manufacturers Association,
Click here to see answer by stanbon(26259) |
Question 181941: Regression analysis of free throws by 29 NBA teams during the 2002-2003 season revealed the fitted regression Y = 55.2 + .73X (R2 = .874, Syx = 53.2) where Y = total free throws made and X = total free throws attempted. The observed range of X was from 1, 620 (New York Knicks) to 2,383 (Golden State Warriors) (a.) Find the expected number of free throws made for a team that shoots 2,000 free throws. (b.) Do you think that the intercept is meaningful? Hint: Make a scatter plot and let Excel fit the line (c.) Use the quick rule to make a 95 percent predicition interval for Y when X = 2,000.
FGP FTP Points Fouls TrnOvr
FGP 1.000
FTP - 0.039 1.000
Points 0.475 0.242 1.000
Fouls - 0.014 0.211 0.054 1.000
TrnOvr 0.276 0.028 0.033 0.340 1.000
Rbnds 0.436 0.137 0.767 - 0.032 0.202
Click here to see answer by stanbon(26259) |
Question 182350: I need step by step answer to this problem, very clearly layed out. I want to be able to understand this step by step answer to each point below. thanks. Stacey
Introduction:
A potato chip company packages its potato chips into 12.0 ounce bags. You find it hard to believe that the bag contains enough potato chips to weigh 12.0 ounces and would like to make an official complaint. Before doing so, you decide to run an experiment so that you can have some confidence that the company’s claim is incorrect. Over the next several months you buy 30 bags of potato chips and weigh the contents of each one. You discover that the mean weight is 11.9 ounces with a standard deviation of 0.4 ounces. You decide that you will only complain if you can be 95% sure that the bags do not contain at least 12.0 ounces of potato chips. You decide to construct a hypothesis test.
Task:
A. Determine if this is a one-tailed or two-tailed test. Justify your decision.
B. State the null hypothesis and alternative hypothesis, including the parameters on both statements. Your null hypothesis should assume the company’s claim is correct.
C. In a discussion of type I errors, do the following:
1. Define the term type I error.
2. Explain what a type I error is in terms of this problem.
D. In a discussion of level of significance, do the following:
1. Define the term level of significance.
2. Identify the level of significance for this problem.
E. Calculate the test statistic as a z-score by using the z-test formula. Show all relevant work.
F. Using a standard table, you determine that the critical value is –1.645.
1. Determine if the test statistic allows you to reject the null hypothesis.
2. Explain how you reached this conclusion, including a comment relating the results to the original problem.
Click here to see answer by stanbon(26259) |
Question 182410: A carnival games uses plastic ducks for players to pick. If people chose one with a colored dot, they would win, those with no colored dots would not. In observing 25 games, the results were as follows:
Blue was chosen 7 times or 7 out of 25 or .28 (28%)
Yellow was chosen 5 times or 5 out of 25 or .20 or (20%)
Red was chosen 4 times or 4 out of 25 meaning .16 or 16%
and finally ducks with no dots were chosen 9 out of 25 times or 36% of time...
that much I get, now the question asks...if there are 120 ducks in the game, based on the observations stated above, how many of each color of dot on the duck should there be?
I have tried to multiply each percentage (given above) by the total number of ducks i.e. P(yellow) is .20, so saying 120 * .20, but that gives me 33.6 ducks...well you can't have a percentage of a duck unless it is missing parts!
Can you please tell me slowly and clearly how I would solve the latter half of this problem as I think I am correct on the first part.
Thanks!!!
Click here to see answer by tvandenberg(45) |
Question 182462: Mr. Rodney's English class is made up of 28 students. He has 6 ESL students, 10 remedial student, and 5 advanced learners. ESL students make up 1/5 of the remedial students and 3/5 of the advanced learners.
1.) What is the probability that a student is ESL and remedial?
2.) What is the probability that a student is ESL and an advanced learner?
3.) What is the probability that a student is remedial and NOT ESL?
Thank you for your help.
Click here to see answer by edjones(3292)  |
Question 182563: I need some help solving this problem..
USE THE NORMAL APPROXIMATION OF THE BINOMIAL PROBABILITY
DISTRIBUTION TO SOLVE THE PROBLEM BELOW.
DeKorte Telemarketing Inc. is considering purchasing a machine that randomly
selects and automatically dials telephone numbers. It makes most of its calls
during the evening, so calls to business phones are wasted. The manufacturer of
the machine claims that their programming reduces the calling to business phones
to 15 percent of all calls. To test this claim, the Director of Purchasing at
DeKorte programmed the machine to select a sample of 150 phone numbers.
What is the probability that more than 30 of the phone selected are that of a
business, assuming the manufacturer’s claim is correct?
Click here to see answer by stanbon(26259) |
Question 182649: This is from a worksheet. Mathematics Essentials Grade 8 week 18 pg 52.
I think I've got the right answer, but I don't know how to put it into an equation. That is the part I need help with. Here is the problem:
There are fifty marbles in a sack: red, blue and green. There are ten more green than blue marbles in the sack. The probability of drawing a red or blue marble is one-half. Write and solve an equation to determine how many of each color marble is in the sack.
I figured the answer would be: blue 15, red 10 and green 25. Can you help me determine the equation? And is the answer right?
Click here to see answer by Mathtut(3670) |
Question 182649: This is from a worksheet. Mathematics Essentials Grade 8 week 18 pg 52.
I think I've got the right answer, but I don't know how to put it into an equation. That is the part I need help with. Here is the problem:
There are fifty marbles in a sack: red, blue and green. There are ten more green than blue marbles in the sack. The probability of drawing a red or blue marble is one-half. Write and solve an equation to determine how many of each color marble is in the sack.
I figured the answer would be: blue 15, red 10 and green 25. Can you help me determine the equation? And is the answer right?
Click here to see answer by stanbon(26259) |
Question 182666: I need help solving this problem using the normal approximation of the binomial probability distribution.
It is known that one out of 3 people entering a large department store will make at least one purchase. If a random sample of 81 people is selected, what is the approximate probability that thirty or more of them will make at least one purchase? What is the probability that at most 40 of them will make at least one purchase?
Click here to see answer by stanbon(26259) |
Question 182705: the six sides of a number cube are labeled 1 through 6.if the number cube is rolled 1000 times, what is the best prediction for the number of times the result will be the number 4?explain how you got the answer.PLEASE ANSWER THIS QUESTION AS SOON AS POSSIBLE!!!THIS IS DUE IN 2 DAYS!! :(
Click here to see answer by Mathtut(3670) |
Question 182863: There are 20 questions in a multiple-choice test. Each question has five choices and one correct answer out of these five choices. A student did not study. He/she answers the questions at random. What are the probabilities that he/she makes (i) more than 10-answer right? (ii) exactly eight right?(iii) at most 7 right?
Click here to see answer by stanbon(26259) |
Question 182969: 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?
Click here to see answer by stanbon(26259) |
Question 182826: 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, Descent). Research question: At α = .05, is the cockpit noise level independent of flight phase
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 183061: bob and fred play the following game. Bob rolls a single die. if the result is the number 1,2,3,4,5 bob must pay fred the number of dollars indicated by the number rolled. if a 6 is rolled fred must pay bob $57 dollars.
find freds expectation?
Click here to see answer by stanbon(26259) |
Question 183099This question is from textbook Study Guide: Review
: 13. The 10-number math team randomly selects 4 representatives to send to a meet. What is the probability that the 4 members chosen are the 4 with the lowest math grades?
14. A 5-digit code is given to all cashiers at a store to let them log onto the cash register. What is the probability that an employee receives a code with all 5 numbers the same?
Explain why the events are independent and find the probability.
25. rolling "doubles" 3 times in a row when rolling 2 number cubes
26. selecting a red pen and then a blue pen, when selecting 2 pens from a bag of 10 red and 15 blue pens with replacement
Could you explain how to solve it?
Thank you for your help.This question is from textbook Study Guide: Review
Click here to see answer by stanbon(26259) |
Question 183124: I am having some trouble with understanding binomial distributions, I hope someone could please help me with this problem.
10% of adults say oatmeal raisin is their favorite cookie. You randomly select 12 aldults and ask each to name his or her favorite cookie. Find the probability that the number who say oatmeal raisin is their favorite cookie is
a) exactly four
b) at least four
c) less than four.
I would like to thank you in advance for your help, I need to pass this class.
Click here to see answer by stanbon(26259) |
Question 183156: Hi,
Can you please help me solve for this, Doane−Seward: Applied Statistics in Business and Economics, ch. 15:
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
(This format is cramming the numbers together to make it easier to read - Correct: Yes, got it right, Regular Cola: 7, Diet Cola: 7, Row Total: 14.)
Thank you
Click here to see answer by stanbon(26259) |
Question 183154: Hi,
Can you please help me solve for this, Doane−Seward: Applied Statistics in Business and Economics, ch. 15:
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, Descent). Research question: At α = .05, is the cockpit noise level independent of flight phase? (Data are from Capt. Robert E. Hartl, retired.)
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
(This format is cramming the numbers together to make it easier to read - Noise Level: Low, Climb: 6, Cruise: 2, Descent: 6, Row Total: 14.)
Thank you
Click here to see answer by stanbon(26259) |
Question 183152: Hi,
Can you please help me solve for this, Doane−Seward: Applied Statistics in Business and Economics, ch. 15:
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.)
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
(This format is cramming the numbers together to make it easier to read - Vehicle type: Car, Somerset: 44, Oakland: 49, Great Lakes: 36, Jamestown: 64, Row Total: 193.)
Thank you
Click here to see answer by stanbon(26259) |
Question 183263: Could you find these problems.
1. Form this link"http://i367.photobucket.com/albums/oo120/CHinBieGO/4-1-1-1-1-2.jpg"
Find the probability that a point chosen at random inside the square is not inside the circle.
2. Seven sisters have to choose which day each will wash the dishes. They put equal size pieces of paper each labeled with a day of the week in a hat. What is the probability that the first sister who draws will choose a weekend day?
3. For his garden, Clay has a mixture of 12 white corn seeds, 24 yellow corn seeds, and 16 bi-color corn seeds. If he reaches for a seed without looking, what is the probability that Clay will plant a bi- color corn seed first?
4. Alex has a paper bag of cookies that includes 8 chocolate chip, 4 peanut butter, 6 butterscotch chip, and 12 ginger. Without looking, his friend John reaches in the bag for a cookie. What is the probability that the cookie is peanut butter?
Click here to see answer by stanbon(26259) |
Question 183151: Hi,
Can you please help me solve for this, Doane−Seward: Applied Statistics in Business and Economics, ch. 15:
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?
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 format is cramming the numbers together to make it easier Credits erned: 0-9, Very uncertain: 12, Somewhat certain: 8, Very certain: 3, Row Total: 23.)
Thank you
Click here to see answer by stanbon(26259) |
Question 183136: 1) there are 3 cards in a hat; one is a king,one is a queen and one is an ace. two cards are to be selected at random with replacement using a tree diagram, obtain a smample space for the experiment. then find the probaiblty that a queen and king are selected?
2) assume that a person spins a spiner and is awarded the amount indicated by the pointer. detrimine the persons expection.
4 parts
2-$8
1-$12
1- $1
3) one card is selected from a deck of cards. find the probabilty of selecting a red card or a card less then 4. (note: the ace is a low card)
4) a number cube labeled with numbers 1-6 is tossed. what are the odds of the number being less than 3.
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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