it's believed that as many as 2222% of adults over 50 never graduated from high school. we wish to see if this percentage is the same among the 25 to 30 age group. a) how many of this younger age group must we survey in order to estimate the proportion of non-grads to within 44% with 90% confidence?

The given values are:

p =  22% = 0.22

Zc = 1.645 at 90% confidence level.

margin of error, E = 0.04

The formula we can use here is:

E = sqrt(pq/n) * Zc

 0.04 = sqrt(0.22*(1-0.22)/n)*1.645

n = (0.22*(1-0.22))*(1.645/0.04)^2

n = 290.22

hence minimum sample size = 290 

so far i think you have the right thing going for you just remember soh cah toh

step-by-step explanation:

sine over hypotenuse

cosine   equals adjacent

tangent over hypotenuse