Answer: The test statistic needed to test this claim= 10.92
Step-by-step explanation:
We know that the probability of giving birth to a boy : p= 0.5
i..e The population proportion of giving birth to a boy = 0.5
As per given , we have
Null hypothesis : 
Alternative hypothesis : 
Since 
is right-tailed , so the hypothesis test is a right-tailed z-test.
Also, it is given that , the sample size : n= 291
Sample proportion: 
Test statistic : 
, where n is sample size , 
is sample proportion and p is the population proportion.
i.e. the test statistic needed to test this claim= 10.92
Critical value ( one-tailed) for 0.01 significance level = 
Decision : Since Test statistic value (10.92)> Critical value (2.326), so we reject the null hypothesis .
[When test statistic value is greater than the critical value , then we reject the null hypothesis.]
Thus , we concluded that we have enough evidence at 0.01 significance level to support the claim that the YSORT method is effective in increasing the likelihood that a baby will be a boy.
