11. [-/2.28 Points] DETAILS BBUNDERSTAT13 7.3.026.S.MI. A random sample of medical files is used to estimate the proportion p of all people who have blood type B. USE SALT MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (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 will be within a distance of 0.04 from p? medical files (b) Answer part (a) if you use the preliminary estimate that about 15 out of 90 people have blood type B. (Round your answer up to the nearest whole number.) medical files Need Help? Read It Watch It Master It Submit Answer 12. [-/2.28 Points] DETAILS BBUNDERSTAT13 7.3.027.S. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER How often do we trust a brand recommended online? Let p represent the proportion of the time a consumer trusts a brand that showed up on their social media feed. USE SALT (a) If you have no preliminary estimate for p, how many participants should you include in a random sample to be 80% sure that the point estimate will be within a distance of 0.08 from p? (Round your answer up to the nearest whole number.) participants (b) Suppose that a report stated that 74% of consumers trust a brand recommended on their social media feed. Using this estimate for p, how many participants should you include in a random sample to be 80% sure that the point estimate will be within a distance of 0.08 from p? (Round your answer up to the nearest whole number.) participants