Question

In a study of pregnant women and their ability to correctly predict the sex of their​ baby, 57 of the pregnant women had 12 years of education or​ less, and 40.4 ​% of these women correctly predicted the sex of their baby. Use a 0.01 significance level to test the claim that these women have an ability to predict the sex of their baby equivalent to random guesses. Identify the null​ hypothesis, alternative​ hypothesis, test​ statistic, P-value, and conclusion about the null hypothesis. Use the​ P-value method. Use the normal distribution as an approximation of the binomial distribution. Do the results suggest that their percentage of correct predictions is different from results expected with random​ guesses?

The test statistic of Z=

P value=

Answer 1

Ans:

Ho: p=0.5

HQ:0.5

Test statistic:

z=(0.404-0.50)/sqrt(0.5*(1-0.5)/57)

z=-1.450

p-value=P(z<-1.450)=0.0735

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

There is not sufficient evidence to conclude that their percentage of correct predictions is different from results expected with random​guesses.