The Academy of Orthopedic Surgeons gives a survey result that 80% of women wear shoes that are too small for their feet. A researcher wants to be 99% confident that his proportion is within 4% of the true proportion. How large a sample is necessary? O 543 385 O 666 O 273 Question 25 (1 point) Find the 90% confidence interval for the variance of the heights of maple trees if a sample of 16 trees has a standard deviation of 10.2 feet O 62.4 < o? < 214.9 O 67.5 < o? < 193.4 O74.7 < o? < 221.8 70.0 < o? < 182.6 Question 27 (1 point) A U.S. Web Usage Snapshot indicated a monthly average of 37 Internet visits a particular website per user from home. A random sample of 24 Internet users yielded a sample mean of 41.1 visits with a standard deviation of 5.3. At the 0.01 level of significance, what is the test value for this hypothesis test? 1.86 O-0.77 3.79 0.77