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Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 240856: Find Z when:
The claim is that the proportion of drowning deaths of children attributable to beaches is more than 0.25, and the sample statistics include n = 657 drowning deaths of children with 30% of them attributable to beaches.
Click here to see answer by stanbon(26249)   |
Question 240859: Information from the American Institute of Insurance indicates the mean amount of life insurance per household in the United States is $110,000. This distribution follows the normal distribution with a standard deviation of $40,000.
a. If we select a random sample of 50 households, what is the standard error of the mean?
b. What is the expected shape of the distribution of the sample mean?
c. What is the likelihood of selecting a sample with a mean of at least $112,000?
d. What is the likelihood of selecting a sample with a mean of more than $100,000
e. What is the likelihood of selecting a sample with a mean of more than $100,000 but less than $112,000?
Click here to see answer by stanbon(26249) |
Question 240767: six cards are to be drawn or delt, without replacement, from a deck of 52 cards. In how many ways can this be done if
A. all of the cards to be drawn are clubs?
B. All are to be jacks or queens?
C. None are to be aces?
D. All are to be spades or all not spades?
Click here to see answer by edjones(3291)  |
Question 240763: Powerball jackpot can be won by picking 5 numbers out of 59 numbers then also picking 1 powerball number from a seperate 39 numbers. The order of the first 5 numbers doesn't matter.
A. how many ways are there to pick the first five numbers?
B. How many ways are there to pick the powerball number?
C. How many ways are ther to pick all six numbers? ( the powerball number comes from a different set of numbers than the first five)
Click here to see answer by solver91311(5063)  |
Question 240666: Last q before my exam: Football fans claim that it takes 35 minutes to get out of the stadium after a game when over 30000 fans attend the game.
To determine if the complains are justified , a random sample of 100 fans is taken. The average time it takes these 100 fans to exit the parking is 27 minutes and sample standard deviatian is 7 minutes.
a) Estimate the mean departe time= 27 minutes?
b) Construct a 95% CI for the mean departure time and interpret the result?
Thx soo much for all your help
Click here to see answer by stanbon(26249) |
Question 240241: It is asserted that 80 percent of the cars approaching an individual toll booth in New Jersey are equipped with an E-ZPass transponder. Find the probability that in a sample of six cars:
What is the probability that 10 of the selected policyholders submitted a claim last year?
What is the probability that 10 or more of the selected policyholders submitted a claim last year?
What is the probability that more than 10 of the selected policyholders submitted a claim last year?
Click here to see answer by stanbon(26249) |
Question 240348: A pizza pub is open 7 days a week. The manager allows each of the three employees to select one day off a week. That is the probability all 3 select the same day given that all 3 select a day beginning with the same letter.
Click here to see answer by stanbon(26249) |
Question 240388: English people get a mean of 7 hrs sleep per night. A random sample of 36 students revealed the number of 6.5 hrs sleep per night. The standard deviation of the sample was 1.2 hrs. Is it reasonable to conclude that the students sleep less than english people. Set up your hyptheses and test it with 5% level of significance
Click here to see answer by stanbon(26249) |
Question 240261: I have an idea where to start but would appreciate any guidance you can provide.
Four hundred people apply for three jobs. 110 of the applicants are women.
a) If three persons are selected at random, what is the probability that all are women? (Round the answer to six decimal places.)
(b) If three persons are selected at random, what is the probability that two are women? (Round the answer to six decimal places.)
(c) If three persons are selected at random, what is the probability that one is a woman? (Round the answer to six decimal places.)
(d) If three persons are selected at random, what is the probability that none is a woman? (Round the answer to six decimal places.)
(e) If you were an applicant, and the three selected people were not of your gender, should the above probabilities have an impact on your situation? Why?
(Yes),the probabilities indicate the presence of gender discrimination.
(No),because in the hiring process all outcomes are not equally likely.
Click here to see answer by stanbon(26249) |
Question 240141: Below are weights (in lbs) of glass discarded in one week by randomly selected households.
3.52 8.87 3.99 3.61 2.33 3.21 0.25 4.94
Construct a 95% confidence interval estimate of the mean weight of glass discarded by all households.
Click here to see answer by stanbon(26249) |
Question 240150: In a survey of 745 randomly selected adults, 589 said that it's morally wrong to not report all income on tax returns. Assume that you must conduct a survey to determine the mean income reported on tax returns and you have access to actual tax returns. How many randomly selected tax returns must you survey if you want to be 99% confident that the mean of the sample is within $500 of the true population? Assume the reported incomes have a standard deviation of $28,785.
Click here to see answer by stanbon(26249) |
Question 240143: Do the following. (Round the answers to six decimal places.)
(a)Find the probability of being dealt an "aces over kings" full house (three aces and two kings).
(b)Find the probability of being dealt a full house.
Click here to see answer by stanbon(26249) |
Question 240123: If you want to estimate the mean amount of money spent by car owners on their last car purchase, how many car owners must you survey if you want 95% confidence that your sample mean is in error by no more than $750?(Assume that the standard deviation of amounts spent on car purchases is 14, 227.)
Click here to see answer by stanbon(26249) |
Question 240002: My favorite CD has 11 songs on it, and I have memorized the songs and the order in which they come. I recently loaded it onto my IPOD to listen to it. I wanted to listen to it in the right order, but I had accidentally set the player to shuffle-play the songs from that album in a random order. Assuming the "next to play" song was always equally likely among the choices not yet played, what is the probability that it will play the correct 5 songs in the correct order so that I don't notice the mistake (until after the fifth song)?
Click here to see answer by Alan3354(6041)  |
Question 240040: Find the dample size required to estimate the maen age of required drivers in the United States. Assume that we want 95% confidence that the sample mean is within 1/2 yera of the true mean asge of the population. Also assume that the standard deviation of the population is known to be 12 years.
Click here to see answer by stanbon(26249) |
Question 239740: An initial deposit of $15,000 is made into an account and monthly deposits of $5,000 are made thereafter. Interest is pays at 8% per year. Set up a table to show how much money is in the account at the end of each month for the first 5 months
Click here to see answer by Theo(667)  |
Question 239414: Assume the likelihood that any flight on Northwest Airlines arrives within 15 minutes of the scheduled time is .90. We select four flights from yesterday for study.
1. What is the likelihood all four of the selected flights arrived within 15 minutes of the scheduled time?
2. What is the likelihood that none of the selected flights arrived within 15 minutes of the scheduled time?
3. What is the likelihood at least one of the selected flights did not arrive within 15 minutes of the scheduled time?
Click here to see answer by solver91311(5063) |
Question 239099: question 1: A coin is biased to show 38% heads and 62% tails. The coin is tossed twice. What is the probability that the coin turns up tails on both tosses?
question 2: Find the probability.
If 81% of scheduled flights actually take place and cancellations are independent events, what is the probability that 3 separate flights will take place?
question 3: Suppose P(C) = .048, P(M ∩ C) = .044, and P(M C) = .524. Find the indicated probability.
P[(M ∩ C)']
Click here to see answer by stanbon(26249) |
Question 239107: Toledo university indicate that 50 percent of student change major in their first year a sample of 100 student 48 change major in their first year. is there a significant decrease in the proportion of student change major in their first year test at .05 significance level
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Question 239093: The cost of tuition at Johnson Community College is $ 200 per credit hour. Each student also has to pay $90 in fees. Write an equation that shows the relationship between the total cost, C, and the number of credit hours taken, x.
Click here to see answer by checkley77(7032) |
Question 239082: A normal population has a mean of 12.2 and a standard deviation of 2.5.
a. Compute the z value associated with 14.3.
b. What proportion of the population is between 12.2 and 14.3?
c. What proportion of the population is less than 10?
Click here to see answer by Theo(667) |
Question 239061: There are entrees 17 available at a restaurant. From these, Archie is to choose 4 for his party. How many groups of 4 entrees can he choose, assuming that the order of the entrees chosen does not matter?
Click here to see answer by Theo(667) |
Question 239004: A processor of carrots cuts the green top off each carrot, washes the carrots, and inserts six to a package. Twenty packages are inserted into a box for shipment. To test the mass of the boxes, a few were checked. The mean mass was 9.3kg, the standard deviation 0.23g. How many boxes must the processor sample to be 95% confident that the sample mean does not differ from the population mean by not more than 0.09kg.
Click here to see answer by stanbon(26249) |
Question 238749: Need help to solve this word problem: How many ways can you order a pie when you have 17 alternative toppings which include 4 kinds of cheese, 3 meat toppings, 6 kinds of vegetables and 4 tofu flavoring (each a separate choice for the tofu only). Thanks.
Click here to see answer by stanbon(26249) |
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