Question

A publisher reports that 54% of their readers own a particular make of car. A marketing executive wants to test the claim that the percentage is actually different from the reported percentage. A random sample of 220 found that 50% of the readers owned a particular make of car. Determine the P-value of the test statistic. Round your answer to four decimal places.

Answer 1

Answer and explanation:

Null hypothesis: p is not 54%

Alternative hypothesis : p is equal 54%

First find standard deviation

Standard deviation is:

σ = √[ P ( 1 - P ) / n ] = √[ 0.54×0.46/220 ] =0.033

The z score is calculated p-P/σ = (0.54-0.50)/0.033 = 1.2121

Therefore we can conclude that proportions are not same and fail to reject the null hypothesis