An article in the October 11, 2006, issue of the Washington Post claimed that 15
ID: 3180457 • Letter: A
Question
An article in the October 11, 2006, issue of the Washington Post claimed that 15 % of high school students used cursive writing on the essay portion of the SAT exam in the academic year 2005-2006. Suppose that you want to design a study to estimate this proportion for the following year. How many essays would you need to sample to estimate this proportion to within plusminus 0.05 with 99 % confidence? (Use the 2005-2006 proportion as a reasonable starting guess for how the following year's proportion will turn out.) Round your answer to the nearest integer. Your sample size should be at least b. Describe the two changes you could make to this goal (estimating this proportion to within plusminus 0.05 with 99 % confidence) if you could not afford to sample so many essays. One change you could make is to. Another change you could make is to use a margin-of-error.Explanation / Answer
a)here p=0.15
margin od error E =0.05
for 99% CI, z=2.5758
hence sample size=(p(1-p)(Z/E)2 =339
b) for part b please revert with options so that I can answer it