Question 1: Bob Nale is the owner of Nale's Texaco GasTown. Bob would like to estimate the mean number of litres (L) of gasoline sold to his customers. Assume the number of litres sold follows the normal distribution with a standard deviation of 32 L. From his records, he selects a random sample of 25 sales and finds the mean number of litres sold is 77.

The point estimate of the population mean is 77 litres.

The 90% confidence interval for the population mean is between 66.472 and 87.528 .

So Interpret the meaning of the 90% confidence interval for the population mean is between 66.472 and 87.528 . If 100 such intervals were determined, the population mean would be included in about __________ intervals.

Question 2: :The National Bank, like most other large banks, found that using automatic teller machines (ATMs) reduces the cost of routine bank transactions. National installed an ATM in the corporate offices of the Fun Toy Company. The ATM is for the exclusive use of Fun's 590 employees. After several months of operation, a sample of 100 employees revealed the following use of the ATM machine by Fun employees in a month:

Number of Times

ATM Used Frequency

0 20

1 30

2 20

3 5

4 5

5 20

(a), For estimate of the proportion of employees who do not use the ATM in a month, develop a 90% confidence interval. (Round the final answers to 3 decimal places.)

90% confidence interval is__________ and_________ .

(b). Develop a 90% confidence interval for the mean number of transactions per month. (Round the final answers to 3 decimal places.)

90% confidence interval for the mean number of transaction per month is __________ and __________ .

Question 3: A sample of 46 observations is selected from a normal population. The sample mean is 39, and the population standard deviation is 9.

Conduct the following test of hypothesis using the 0.10 significance level.

H0 : 38

H1 : > 38

What is the decision rule? (Round the final answer to 3 decimal places.)

Reject H0 and accept H1 when z >___________ .

Question 4: The mean mass of the puppies at five months is 4.37 kg. The masses follow the normal distribution. In an effort to increase their mass, a supplement is added to their daily meals. The subsequent masses of a sample of five-month-old puppies were (in kilograms):

4.37 4.55 4.54 4.22 4.57 4.60 4.20 4.48 4.51 4.49

Determine or estimate the p-value.___________ (Round the final answer to 4 decimal places.)

Question 5: The following hypotheses are given.

H0: p 0.49

H1: p > 0.49

A sample of 150 observations revealed that = 0.39. At the 0.10 significance level, can the null hypothesis be rejected?

State the decision rule. (Round the final answer to 3 decimal places.)

Reject H0 and accept H1 if z >_________ or z < ___________ .

Question 6: A Washington, D.C., "think tank" announces the typical teenager sent 67 text messages per day in 2017. To update that estimate, you phone a sample of 12 teenagers and ask them how many text messages they sent the previous day. Their responses were:

51 175 47 49 44 54 145 203 21 59 42 100

State the decision rule for 0.05 significance level. (Round your answer to 3 decimal places.)

Reject H0 if t >_____________.

Question 7: Listed below is the annual rate of return (reported in percent) for a sample of 12 taxable mutual funds.

4.63 4.15 4.76 4.70 4.65 4.52 4.70 5.06 4.42 4.51 4.24 4.52

Compute the value of the test statistic. (Round your answer to 3 decimal places.)

Value of the test statistic________________.