Question

Question 1.1. If 16% of the listeners of a radio station listen to it while they are at work, what is the approximate standard deviation of the sampling distribution of the proportion for samples of size 72?
(Points : 4)
0.5%

1.9%

4.3%

9.3%

Answer 1

Question 2.2. A transportation worker takes a simple random sample of 162 toll booth receipts for one day and finds that the mean is $7.38 with a standard deviation of $1.45. What is the 99% confidence interval for the mean amount of all the receipts that day?
(Points : 4)
($7.30, $7.46)

($7.27, $7.49)

($7.16, $7.60)

($7.09, $7.67)



Question 3.3. In a random sample of 63 women at a company, the mean salary is $48,902 with a standard deviation of $5270. In a random sample of 50 men at the company, the mean salary is $53,454 with a standard deviation of $4677. Construct a 95% confidence interval for the difference between the mean salaries of all women and men at the company.
(Points : 4)
($2134.05, $6969.95)

($2715.11, $6388.89)

($3614.81, $5489.19)

($4083.40, $5020.60)

Question 5.5. A simple random sample of 1800 hospital patients admitted in a given year shows that 82.5% had an error on their medical bill. What is the 95% confidence interval for the percent of all the hospital's admitted patients admitted that year who had an error on their medical bill?
(Points : 4)
(82.0, 83.0)

(81.6, 83.4)

(80.7, 84.3)

(80.2, 84.8)



Question 6.6. In a simple random sample of 298 students at a college, 87 reported that they have at least $1000 of credit card debt. What is the 99% confidence interval for the percent of all the students at that college who have at least $1000 in credit card debt?
(Points : 4)
(26.5, 31.9)

(24.8, 33.6)

(22.4, 36.0)

(21.8, 36.6)