A researcher wants to show that fewer than 40 of the populat

A researcher wants to show that fewer than 40% of the population exercise regularly. He samples 900 individuals and 342 of them exercise regularly. What is the value of the test statistic?

            A.      

z = -1.22

            B.      

z = -2.05

            C.      

z = -1.53

Solution

Test Statistic
No. Of Success chances Observed (x)=342
Number of objects in a sample provided(n)=900
No. Of Success Rate ( P )= x/n = 0.38
Success Probability   ( Po )=0.4
Failure Probability ( Qo) = 0.6
we use Test Statistic (Z) for Single Proportion = P-Po/Sqrt(PoQo/n)
Zo=0.38-0.4/(Sqrt(0.24)/900)
Zo =-1.22