Question

A medical researcher says that less than 80% of adults in a certain country think that healthy children should be required to be vaccinated. In a random sample of 500 adults in that country, 78% think that healthy children should be required to be vaccinated. At a = 0.01, is there enough evidence to support the researcher's claim? Complete parts (a) through (e) below.

​(c) Find the standardized test statistic z.

z=

Answer 1

Ans:

Ho:p> 0.80

Ha: p < 0.80

n=500

sample proportion=0.78

c)

Test statistic:

z=(0.78-0.80)/sqrt(0.80*(1-0.80)/500)

z=-1.118

p-value=P(z<-1.118)=0.1318

As,p-value>0.01,we fail to reject the null hypothesis.

There is not sufficient evidence to support the researcher's claim.