SOLUTION: As a condition of employment, Fashion Industries applicants must pass a drug test. Of the last 225 applicants, 20 failed the test. (Use z Distribution Table.) a. Develop a 9

Algebra ->  Probability-and-statistics -> SOLUTION: As a condition of employment, Fashion Industries applicants must pass a drug test. Of the last 225 applicants, 20 failed the test. (Use z Distribution Table.) a. Develop a 9      Log On


   



Question 1092898: As a condition of employment, Fashion Industries applicants must pass a drug test. Of the last 225 applicants, 20 failed the test. (Use z Distribution Table.)

a.
Develop a 95% confidence interval for the proportion of applicants that fail the test. (Round your answers to 3 decimal places.)

For the applicants the confidence interval is between ____ and ____.

b. Would it be reasonable to conclude that more than 8% of the applicants fail the test?


Yes
No

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
p hat is 20/225=0.089
95% CI is phat +/- 1.96* sqrt(p*(1-p))/n
half interval is 1.96+/- sqrt (0.089*0.911)/225); sqrt term = 0.0190, and product is 0.037
interval is (0.052, 0.126)
No, since every value in the interval is possible one may say that values below 5.2% would not be consistent nor values above 12.7%. But the values between 5.2 and 8% are entirely feasible.