Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 285124: We saw last week that if the probability that a women is rich is 0.4, the probability that she is beautiful is 0.3, and the probability that she is either rich or beautiful is 0.5, then we can show that the probability that she is both rich AND beautiful equals 0.2
What is the probability that a rich woman is beautiful?
Click here to see answer by Edwin McCravy(8909)   |
Question 285332: A department store manager claims that at least 45% of persons who visited this store make a purchase. In a sample of 400 persons who visited the store 150 made a purchase. Test the manager’s claim at the 3% significance level.
Which equation listed below would you use?
Click here to see answer by stanbon(57361) |
Question 285330: A department store manager claims that at least 45% of persons who visited this store make a purchase. In a sample of 400 persons who visited the store 150 made a purchase. Test the manager’s claim at the 3% significance level.
Click here to see answer by stanbon(57361) |
Question 285319: 1. A recent survey by the American Accounting Association revealed 23% of students graduating with an Accounting degree chose public accounting. Suppose we select a sample of 15 students.
a. What is the probability exactly two select public accounting?
b. What is the probability exactly five select public accounting?
c. How many graduates would you "expect" to select public accounting?
Click here to see answer by stanbon(57361) |
Question 285308: shawn and maddie purchase a foreclosed property for $50,000 and spend an additional $27,000 fixing up the property. They feel they can sell the property for $120,000 with probabilty 15%, $100,000 with probability 45%, $80,000 with probability 25% and $60,000 with probability 15%. Compute and interpret the expected profit for reselling the property
Click here to see answer by stanbon(57361) |
Question 285378: 1. if you draw a card from a deck of 52 cards and you're paid $5.00 if it's a red card. What is the expected value?
2in an experiment of rolloing a die, what is the probability of having a number divisible by 3?
3 if 3 dice are rolled, what's the probability of getting a "1" on all dice?
4 if 2 dice are rolled and 2 coins are tossed at the same time, what is the probability of dice getting both "1" and coins getting both heads?
Click here to see answer by stanbon(57361) |
Question 285534: Provide an example of a situation that describes a permutation?
Provide a situation that describes a combination?
How many different plates are possible in the United Kingdom?
Identify the probability that a randomly selected plate is AA 51 ZZZ?
Click here to see answer by Theo(3464)  |
Question 285605: A book store owner decides to sell children’s talking books that will appeal to the middle 34% of his customers. The owner studies that mean price of children’s talking books is $34.80 with a standard deviation of $9.50. Find the minimum price of talking books the owner should sell. Assume the variable is normally distributed.
Click here to see answer by stanbon(57361) |
Question 285612: It has been determined that the wait-time for a particular doctor is normally distributed with a mean of 28 minutes and a standard deviation of 2 minutes. What is the probability that you will wait between 26 and 32 minutes? Please round the answer to four decimal places.
Click here to see answer by stanbon(57361) |
Question 285578: in a recent survey of 25 voters, 17 favor a new city regulation and 8 oppose it. what is the probability that in a random sample of 6 respondents from this survey, exactly 2 favor the proposed regulation 4 oppose it?
Click here to see answer by stanbon(57361) |
Question 285518: suppose you are writing a multiple choice exam in which each answer has 5 choices. you decide to use in which you place 5 balls in a box (marked A,B,C,D,E). you randomly select 1 ball for each question and replace it, the marking on the ball determines your answer to the question. If there are 10 questions,
1. what is the probability of getting 5 questions correct?
2. getting at least 3 questions correct?
3. what is the expected number of correct answers?
4. what is the standard deviation?
Click here to see answer by stanbon(57361) |
Question 285518: suppose you are writing a multiple choice exam in which each answer has 5 choices. you decide to use in which you place 5 balls in a box (marked A,B,C,D,E). you randomly select 1 ball for each question and replace it, the marking on the ball determines your answer to the question. If there are 10 questions,
1. what is the probability of getting 5 questions correct?
2. getting at least 3 questions correct?
3. what is the expected number of correct answers?
4. what is the standard deviation?
Click here to see answer by richwmiller(9143)  |
Question 285510: In how many different ways can the top eight new indie bands be ranked on a top eight list? The top hit song for each of the eight bands will compete to receive monetary awards of $1000, $500 and $250, respectively. In how many ways can the awards be given out?
Click here to see answer by stanbon(57361) |
Question 285511: How many different ways are there for an admissions officer to select a group of 8 college candidates from a group of 12 applicants for an interview?
and
Which pair has equally likely outcomes? List the letters of the two choices below which have equal probabilities of success, separated by a comma.
A. rolling a total of 4 on two fair six sided dice
total possible combinations = 3 (1,3 and 3,1 and 2,2)
total sample size is ???
3 / ???
B. drawing a black seven out of a standard 52 card deck given it’s not a face card or an ace.
2 / (52-16) = 2/36 = 1/18
C. rolling a total of 11 on two fair six sided dice ??
D. rolling a total of 7 on two fair six sided dice ??
E. drawing a three out of a standard 52 card deck given it’s not a face card or an ace.
3 / (52-16) = 3/39 = 1/13
Click here to see answer by stanbon(57361) |
Question 285509: Can someone help me PLEASE, I am completely stuck and I can not even think on where to begin, I have tried and tried and come up with different answers each time.
A teacher wishes to compare two different groups of students with respect to their mean time to complete a standardized test. The time required is determined for each group. The data summary is given below. Test the claim at = 0.10, that there is no difference in variance. Give the critical region, test statistic value, and conclusion for the F test.
n1 = 40 s1 = 44
n2 = 60 s2 = 74
= 0.10
I need to find the · State the null and alternate hypotheses.Determine which test statistic applies, and calculate it.Determine the critical region. State your decision: Should the null hypothesis be rejected?”
You are given the following data. Test the claim that there is a difference in the means of the two groups. Use = 0.01.
Group A Group B
= 7 = 10
= 12 = 11
= 66 = 92
State the null and alternate hypotheses
Determine which test statistic applies, and calculate it
Determine the critical value(s).
State your decision: Should the null hypothesis be rejected?
I need these answers A.S.A.P. please I am already having a very hard time with this class and my teachers patience is wearing very thing, Thank you sooooo very much for your time
Click here to see answer by stanbon(57361) |
Question 285509: Can someone help me PLEASE, I am completely stuck and I can not even think on where to begin, I have tried and tried and come up with different answers each time.
A teacher wishes to compare two different groups of students with respect to their mean time to complete a standardized test. The time required is determined for each group. The data summary is given below. Test the claim at = 0.10, that there is no difference in variance. Give the critical region, test statistic value, and conclusion for the F test.
n1 = 40 s1 = 44
n2 = 60 s2 = 74
= 0.10
I need to find the · State the null and alternate hypotheses.Determine which test statistic applies, and calculate it.Determine the critical region. State your decision: Should the null hypothesis be rejected?”
You are given the following data. Test the claim that there is a difference in the means of the two groups. Use = 0.01.
Group A Group B
= 7 = 10
= 12 = 11
= 66 = 92
State the null and alternate hypotheses
Determine which test statistic applies, and calculate it
Determine the critical value(s).
State your decision: Should the null hypothesis be rejected?
I need these answers A.S.A.P. please I am already having a very hard time with this class and my teachers patience is wearing very thing, Thank you sooooo very much for your time
Click here to see answer by richwmiller(9143) |
Question 285475: The health of employees is monitored by periodically weighing them in. A sample of 54
employees has a mean weight of 175.2 lb. Assuming that is known to be 121.2 lb, use a
0.10 significance level to test the claim that the population mean of all such employees
weights is less than 200 lb.
Perform a hypothesis test
Click here to see answer by stanbon(57361) |
Question 285680: At Ajax Spring Watewr, a half-liter bottle of soft dring is supposed to contain a mean of 520 ml. The filling process follows a normal distribution with a known process standard deviation of 4 ml. (a) which sampling distribution would you use if random samples of 10 bottles are to be weighed? Why? (b) Set up hypothesis and a two-tailed decision rule for the correct mean using the 5 percent level of significance. (c) I f a sample of 16 bottles shows a mean fill of 515 ml. does this contradict the hypothesis that the true mean is 520 ml?
Click here to see answer by stanbon(57361) |
Question 285646: faced with rising fax costs a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. the firm examined 35 randomly chosen fax transmissions during the next year, yielding a sample mean of 14.44 with a standard deviation of 4.45 pages. (a) at the .01 level of significance, is the true mean greater than 10? (b) use excel to find the right-tail p-value.
Click here to see answer by stanbon(57361) |
Question 285683: Ages for the 2005 Boston Red Sox pitchers are shown below. (a) Assuming this is a random sample of major league pitchers, at the 5 percent level of significance does this sample show that the true mean age of all American League pitchers is over 30 years? State your hypothesis and decision rule and show all work. (b) If there is a difference, is it important? (c) Find the p-value and interpret it.
Click here to see answer by richwmiller(9143) |
Question 285643: A medical research project examined the relationship between a subject’s weight and recovery time from a surgical procedure, as shown in the table below.
Underweight Normal weight Overweight
Less than 3 days 6 15 3
3 to 7 days 30 95 20
Over 7 days 14 40 27
a. What is the probability a patient will recover in fewer than 3 days?
b. Given that recovery takes over 7 days, what is the probability the patient is overweight?
Click here to see answer by stanbon(57361) |
Question 285790: A bag contains 3 red chips, 2 blue chips, and 1 white chip. If 2 chips are chosen from the bag(without replacement), the probability that they are different colors is
A. 11/30 B. 11/15 C. 4/15 D. 2/15 E. None of these.
Click here to see answer by stanbon(57361) |
Question 285787: Find E(X)and E(X2)for the probability distribution from the following data.X=8, 12, 16, 20, 24, P(X)=1/8, 1/6, 3/8, 1/4, 1/12,
Click here to see answer by stanbon(57361) |
Question 285821: Which one of the following is not a condition of the binomial distrbution?
a. independent trials
b. only two out comes
c. probability of success remains constant from trial to trial
d. at least 10 observations
c. none of the above
Click here to see answer by stanbon(57361) |
Question 285831: Rolex determines the world rankings for female golfers on the LPGA tour. During a recent golf event, the top 3 players in the rankings were paried together for the first group of the day. If there are 70 players on the tour, how many different pairings are possible for that first group of the day.
DO NOT SOLVE. JUST NEED TO KNOW WHICH FORMULA.
a.Special rule of addition
b. general rule of addition
c. special rule of multiplication
d. genreal rule of multiplication
e. permutation
f. combination
g. multiplication counting formula
h. binomial
i. binomial
j. normal
k. normal approximation to the binomial
Click here to see answer by stanbon(57361) |
Question 285830: The mean amount spent by a family of four on food per month is $500 with a standard deviation of $75. Assuming that the food costs are normally distrubuted, what is the probability that a family spends less than $ 410 per month.
DO NOT SOLVE. JUST NEED TO KNOW WHICH FORMULA.
a.Special rule of addition
b. general rule of addition
c. special rule of multiplication
d. genreal rule of multiplication
e. permutation
f. combination
g. multiplication counting formula
h. binomial
i. binomial
j. normal
k. normal approximation to the binomial
Click here to see answer by stanbon(57361) |
Question 285824: If two events are independent, then their joint probability is
a. computed with the special rule of addition
b. computed with the special rule of multiplication
c. computed with the general rule of mutiplication
d. computed with the Bayes theorem
Click here to see answer by stanbon(57361) |
Question 285742: 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
Click here to see answer by stanbon(57361) |
Question 285842: I am totally math challenged and a graduate student, but at this time I am going through a serious mental challenge of being totally burned out. Can someone please help me with this. My e-mail address is jeannemonger@gmail.com. Any help would be appreciated.
For the population of people who suffer occasionally from migrane headaches, suppose p=0.60 is the proportion who get some relief from taking Ibuprofen. For a particular subject let x=1 if they get relief and x=0 if they do not. For a random sample of 24 people who suffer from migrane headaches:
a. State the population distribution (that is, the probability distribution of X for each observation.
b. Find the mean of the sampling distribution of the sample proportions who got relief among the 24 people.
c. Find the standard error of the sampling distribution of the sample proportion who got relief among the 24 people.
c. Find the standard error of the sampling distribution of the sample proportion of relief for the 24 people.
d. Explain what the standard error describes.
Click here to see answer by unlockmath(1602)  |
Question 285856: Five numbers are to be picked, without repetition, from 44 numbers to determine the winner of the Fortune Five game in the state lottery. If the order of the numbers is insignificant, how many different ways can a winning quintuple be selected? What is the probability of winning?
Click here to see answer by stanbon(57361) |
Question 285878: A gas station manager thinks the average motorist changes their oil less than the recommended two times per year. In a survey 15 car owners were asked how many times they changed their oil in the past year. Here are the results:
1 1 2 1 2
2 0 1 0 1
2 3 1 3 0
The value of the test statistic is equal to _____________ ?
Answer between two and four decimals
Thank you for any help that you can provide!
Click here to see answer by stanbon(57361) |
Question 285901: A corporate CEO reviews the earnings of three divisions over the last eighteen months. Each division reports its earnings quarterly. Based on the earnings below, is there sufficient evidence to conclude, at the 99% level of confidence, that one of these divisions is more profitable than the others?
Division I Division II Division III
42 40 7
39 32 1
32 27 11
1 11 15
49 25 16
54 23 8
· State the null and alternate hypotheses
· Calculate the sums of squares SS(total), SS(factor), and SS(error)
· Calculate the degrees of freedom df(total), df(factor), and df(error)
· Calculate the mean square for factor, and the mean square for error
· Calculate the F-statistic
· Determine the critical value(s)
· State your decision: Should the null hypothesis be rejected?
Click here to see answer by stanbon(57361) |
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7606..7650, 7651..7695, 7696..7740, 7741..7785, 7786..7830, 7831..7875, 7876..7920, 7921..7965, 7966..8010, 8011..8055, 8056..8100, 8101..8145, 8146..8190, 8191..8235, 8236..8280, 8281..8325, 8326..8370, 8371..8415, 8416..8460, 8461..8505, 8506..8550, 8551..8595, 8596..8640, 8641..8685, 8686..8730, 8731..8775, 8776..8820, 8821..8865, 8866..8910, 8911..8955, 8956..9000, 9001..9045, 9046..9090, 9091..9135, 9136..9180, 9181..9225, 9226..9270, 9271..9315, 9316..9360, 9361..9405, 9406..9450, 9451..9495, 9496..9540, 9541..9585, 9586..9630, 9631..9675, 9676..9720, 9721..9765, 9766..9810, 9811..9855, 9856..9900, 9901..9945, 9946..9990, 9991..10035, 10036..10080, 10081..10125, 10126..10170, 10171..10215, 10216..10260, 10261..10305, 10306..10350, 10351..10395, 10396..10440, 10441..10485, 10486..10530, 10531..10575, 10576..10620, 10621..10665, 10666..10710, 10711..10755, 10756..10800, 10801..10845, 10846..10890, 10891..10935, 10936..10980, 10981..11025, 11026..11070, 11071..11115, 11116..11160, 11161..11205, 11206..11250, 11251..11295, 11296..11340, 11341..11385, 11386..11430, 11431..11475, 11476..11520, 11521..11565, 11566..11610, 11611..11655, 11656..11700, 11701..11745, 11746..11790, 11791..11835, 11836..11880, 11881..11925, 11926..11970, 11971..12015, 12016..12060, 12061..12105, 12106..12150, 12151..12195, 12196..12240, 12241..12285, 12286..12330, 12331..12375, 12376..12420, 12421..12465, 12466..12510, 12511..12555, 12556..12600, 12601..12645, 12646..12690, 12691..12735, 12736..12780, 12781..12825, 12826..12870, 12871..12915, 12916..12960, 12961..13005, 13006..13050, 13051..13095, 13096..13140, 13141..13185, 13186..13230, 13231..13275, 13276..13320, 13321..13365, 13366..13410, 13411..13455, 13456..13500, 13501..13545, 13546..13590, 13591..13635, 13636..13680, 13681..13725, 13726..13770, 13771..13815, 13816..13860, 13861..13905, 13906..13950, 13951..13995, 13996..14040, 14041..14085, 14086..14130, 14131..14175, 14176..14220, 14221..14265, 14266..14310, 14311..14355, 14356..14400, 14401..14445, 14446..14490, 14491..14535, 14536..14580, 14581..14625, 14626..14670, 14671..14715, 14716..14760, 14761..14805, 14806..14850, 14851..14895, 14896..14940, 14941..14985, 14986..15030, 15031..15075, 15076..15120, 15121..15165, 15166..15210, 15211..15255, 15256..15300, 15301..15345, 15346..15390, 15391..15435, 15436..15480, 15481..15525, 15526..15570, 15571..15615, 15616..15660, 15661..15705, 15706..15750, 15751..15795, 15796..15840, 15841..15885, 15886..15930, 15931..15975, 15976..16020, 16021..16065, 16066..16110, 16111..16155, 16156..16200, 16201..16245, 16246..16290, 16291..16335, 16336..16380, 16381..16425, 16426..16470, 16471..16515, 16516..16560, 16561..16605, 16606..16650, 16651..16695, 16696..16740, 16741..16785, 16786..16830, 16831..16875, 16876..16920, 16921..16965, 16966..17010, 17011..17055, 17056..17100, 17101..17145, 17146..17190, 17191..17235, 17236..17280, 17281..17325, 17326..17370, 17371..17415, 17416..17460, 17461..17505, 17506..17550, 17551..17595, 17596..17640, 17641..17685, 17686..17730, 17731..17775, 17776..17820, 17821..17865, 17866..17910, 17911..17955, 17956..18000, 18001..18045, 18046..18090, 18091..18135, 18136..18180, 18181..18225, 18226..18270, 18271..18315, 18316..18360, 18361..18405, 18406..18450, 18451..18495, 18496..18540, 18541..18585, 18586..18630, 18631..18675, 18676..18720, 18721..18765, 18766..18810, 18811..18855, 18856..18900, 18901..18945, 18946..18990, 18991..19035, 19036..19080, 19081..19125, 19126..19170, 19171..19215, 19216..19260, 19261..19305, 19306..19350, 19351..19395, 19396..19440, 19441..19485, 19486..19530, 19531..19575, 19576..19620, 19621..19665, 19666..19710, 19711..19755, 19756..19800, 19801..19845, 19846..19890, 19891..19935, 19936..19980, 19981..20025, 20026..20070, 20071..20115, 20116..20160, 20161..20205, 20206..20250, 20251..20295, 20296..20340, 20341..20385, 20386..20430, 20431..20475, 20476..20520, 20521..20565, 20566..20610, 20611..20655, 20656..20700, 20701..20745, 20746..20790, 20791..20835, 20836..20880, 20881..20925, 20926..20970, 20971..21015, 21016..21060, 21061..21105, 21106..21150, 21151..21195, 21196..21240, 21241..21285
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