In: Statistics and Probability
A publisher reports that 62% 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 56% of the readers owned a particular make of car. Find the value of the test statistic. Round your answer to two decimal places.
SOLUTION:
From given data,
A publisher reports that 62% 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 56% of the readers owned a particular make of car.
p = 62% = 62/100 = 0.62
The null and alternative hypotheses are
: p = 0.62
versus
: p 0.62
n = 220
x = (220/100)*56 = 123.2
The sample proportion is
= x/n = 123.2/220 = 0.56
Find the value of the test statistic. Round your answer to two decimal places.
The formula for calculating the test statistic is given by,
z = ( - p) / sqrt (p(1-p)/n)
z = (0.56 - 0.62) / sqrt (0.62(1-0.62)/220)
z =-1.83
The test statistic = z = -1.83 (Round your answer to two decimal places)