Question

Suppose that of 1000 customers surveyed, 850 are satisfied or very satisfied with a corporation’s products and services.

a. Test the hypothesis H0: p=0.9 against H1: p!=0.9 at α = 0.05. Find the P-value.

b. Explain how the question in part (a) could be answered by constructing a 95% two-sided confidence interval for p.

Answer 1

Hyphotesis statement

Let X be random variable of number of customers are satisfied or vary satisfied with corporation's product and service

given

X=850 ;n=1000

as n=1000 is large so we can use central limit theorem of normal approximation.

# a)

under H0 we test statistics

Zo=-5.27

# b 95% confidence interval for p

(0.83,0.87)--------------------ans

As confidence interval does not contain 0.9

it means we can say there is 95 % prabability  that P is not equal to

P <> 0.9 means accepting H1