9. A survey of 280 homeless persons showed that 63 were veterans. Construct a 90% confidence interval for the proportion of homeless persons who are veterans.

In a social study, a random sample of 150 teachers were selected and an independent random sampleof 100 nurses were selected. Each person was asked if they currently have a second job. The resultsshowed that 48 of the 150 teachers and 21 of the 100 nurses had a second job. Construct and interpreta 95% confidence interval for the difference in the proportion of all teachers and nurses that have asecond job.

A random sample of 30 professional tennis players is selected. For each tennis player, their first serve percentage and their second serve percentage are recorded. A 95% confidence interval for the mean difference (first – second) in serve percentages is found to be 0.10 to 0.18. A tennis coach claims that there is no difference in first and second serve percentages among professional tennis players. Is this claim supported by the confidence interval? No, the confidence interval does not contain the value of 0. Yes, the confidence interval does not contain the value of 0. No, the confidence interval does not contain negative numbers. Yes, the confidence interval consists entirely of positive numbers.

A survey found that 611 out of 663 college graduates cannot correctly spell the word aluminum. Find a 76% confidence interval for the percent of college graduates that have this speling problem.Use 4 decimal places