Statistics and Probability Answers

A.     Using the t-table, give the confidence coefficients for each of the following:

a. _n=21, 95% confidence

b. _n=26, 99% confidence

B.     Compute the population proportion interval estimate given , and the confidence level.

a. _{n=420;p-hat=0.61}, 95% confidence

b. _{n=960;p-hat=0.17}, 99% confidence

C.     Estimate the interval for the population proportion from each of the following. Then, interpret the results.

a. x=_{610, n=1050}, 95% confidence

b. x=_{734, n=1540}, 99% confidence

The number of driving miles before a certain type of tire begins to show wear is on the average 18,200 miles with a standard deviation σ = 3,500 miles. If Jack Car Rental Agency buys 25 of these tires for replacement purposes and parts each one on a different car, compute the mean μ x̅ and standard deviation σ x̅ of the sampling distribution of the sample means.

In Two independent tosses of an unbiased coin the sample space set contains ….elements

1. 4
2. 3
3. 2
4. 1

The significance level is the risk of:

1. Rejecting Ho when Ho is correct
2. Rejecting Ho when H1 is correct
3. Rejecting H1 when H1 is correct
4. Accepting Ho when Ho is correct

In hypothesis testing the type of the test to be used (one or two tailed) is determined by

The mean number of hours a Filipino worker spends on the computer is 3.1 hours per workday. Assume the standard deviation is 0.5 hours and is normally distributed, how long does a worker spend on the computer if his z-score is 1.2?

1. Find the value of the finite population correction factor when:

a)   n = 10 and N = 10000

b)   n = 40 and N= 10,000

How a large sample should be surveyed to estimate the true proportion of college students who do a laundry once a week within 3% with 95% confidence?

Let X denote the random variable distribution that gives 2,3,4,5,6,7,8,9 and 10 in a deck

of cards. Find the probability of X.