11. [-/0.2 Points] DETAILS BBUNDERSTAT12 7.3.023.MI.S. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding. A random sample of medical files is used to estimate the proportion p of all people who have blood type B. LA USE SALT a) If you have no preliminary estimate for p, how many medical files should you include in a random sample in order to be 85% sure that the point estimate p will be within a distance of 0.06 from p? (Round your answer up to the nearest whole number.) medical files (b) Answer part (a) if you use the preliminary estimate that about 10 out of 90 people have blood type B. medical files Need Help? Read It Watch It Master 12. [-/0.2 Points] DETAILS BBUNDERSTAT12 7.3.024.S. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding. How hard is it to reach a businessperson by phone? Let p be the proportion of calls to businesspeople for which the caller reaches the person being called on the first try. LA USE SALT (a) If you have no preliminary estimate for p, how many business phone calls should you include in a random sample to be 80% sure that the point estimate p will be within a distance of 0.07 from p? (Round your answer up to the nearest whole number.) phone calls b) A report states that businesspeople can be reached by a single phone call approximately 23% of the time. Using this (national) estimate for p, answer part (a). (Round your answer up to the nearest whole number.) phone calls Need Help? Read It 13. [-/0.3 Points] DETAILS BBUNDERSTAT12 7.3.025.FB.S. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding. What percentage of your campus student body is female? Let p be the proportion of women students on your campus. In USE SALT (a) If no preliminary study is made to estimate p, how large a sample is needed to be 99% sure that a point estimate p will be within a distance of 0.04 from p? (Round your answer up to the nearest whole number.) students (b) A report indicates that approximately 57% of college students are females. Answer part (a) using this estimate for p. (Round your answer up to the nearest whole number.) students Need Help? Read it Watch It