Last year, 35% of people who downloaded a free “app “(application) for their mobile electronics device deleted the downloaded app within 6 months of the download. Acme games recently conducted a survey of 200 randomly selected customers who had downloaded its most popular app 6 or more months ago. The company wanted to determine if the 35% deletion rate was true for their app. Suppose 64 of the 200 customers in the sample reported deleting the app within 6 months of download. 

a. Use the normal sampling distribution of the sample proportion to test a null hypothesis that the deletion rate for Acme’s app is 35%. Use a significance level of .05. 

b. Use a chi square test and a significance level of .05 to test the null hypothesis in part a.