In: Statistics and Probability
A STUDY OF CUSTOMERS’ PREFERENCES IS DESIGNED. THE MARKET RESEARCH SPECIALISTS WANT TO ESTIMATE PROPORTION OF SATISFIED CUSTOMERS AT THE SPECIFIED CONFIDENCE LEVEL (= C) AND ENSURE THAN THE MARGIN OF ERROR DOES NOT EXCEED THE BOUND (= E).
(A) SET THE 90% CONFIDENCE LEVEL AND BOUND
EQUAL TO 2.9%. WHAT IS THE SMALLEST SAMPLE
SIZE NEEDED?
SHOW THE FORMULA AND CALCULATIONS, PLEASE.
CRITICAL VALUE =
SAMPLE SIZE =
WILL THE SAMPLE OF SIZE 900 BE SUFFICIENT?
(B) THE DIRECTOR OF MARKET RESEARCH DIVISION WANTS A 99% CONFIDENCE INTERVAL WITH THE MARGIN OF ERROR WITHIN ± 3.5%.
WHAT IS THE SMALLEST SAMPLE SIZE NEEDED? SHOW THE FORMULA AND CALCULATIONS, PLEASE.
CRITICAL VALUE =
SAMPLE SIZE =
WILL THE SAMPLE OF SIZE 900 BE SUFFICIENT?