Question:
You obtain an internship working in the fraud division of the District Attorney' office. One of the investigators believes that there is a tendency for those writing fraudulent checks to begin them with the number 5. He asks you to take a sample of the checks that were submitted as evidence in fraud cases where the company was found guilty to substantiate his belief. You randomly sample a total of 325 checks and find that 48% had amounts that began with the number 5. Construct a 90% confidence interval of the population proportion of fraudulent checks that begin with the number 5. The District Attorney would like to be able to use this to screen for valid fraud cases to prosecute. Based on your results would you recommend that to him? Please explain your answer