Question

a) A bank randomly selected 250 checking account customers and found that 113 of them also had savings accounts at this same bank. Construct a 95% confidence interval for the true proportion of checking account customers who also have savings accounts. (Give your answers correct to three decimal places.)

Upper Limit -

Lower Limit -

b) In a sample of 50 randomly selected students, 29 favored the amount being budgeted for next year's intramural and interscholastic sports. Construct a 95% confidence interval for the proportion of all students who support the proposed budget amount. (Give your answers correct to three decimal places.)

Upper Limit -

Lower Limit -

c) Calculate the value of t for the hypothesis test. (Give your answer correct to two decimal places.)

H_o: μ = 32, H_a: μ > 32, n = 17, x = 32.56, s = 2.6

Answer 1

Solution: a) Here the given information are

n=250, x=113

=x/n= 113/250 = 0.452

95% confidence interval for proportion is calculated as follows

Substituting our values we get

(0.390, 0.514)

Lower limit=0.390

Upper limit=0.514

b) Here the given information are

n=50, x=29

=x/n=29/50 = 0.58

95% confidence interval for proportion is calculated as follows

(0.443, 0.717)

Lower limit=0.443

Upper limit=0.717

c) Here the given information are

Ho: μ = 32, Ha: μ > 32, n = 17, x = 32.56, s = 2.6

t=0.88