Preparing to Test a Claim about a Population Proportion
Question 10 • CA-Statistics and Probability B
It is claimed that 95% of teenagers who have a cell phone never leave home without it. To investigate this claim, a random sample of 300 teenagers who have a cell phone was selected. It was discovered that 273 of the teenagers in the sample never leave home without their cell phone. One question of interest is whether the data provide convincing evidence that the true proportion of teenagers who never leave home without a cell phone is less than 95%. The standardized test statistic is z = –3.18 and the P-value is 0.0007. What decision should be made using the = 0.01 significance level?
Answer
A
Reject H0 because the P-value is less than = 0.01.
B
Reject H0 because the test statistic is less than = 0.01.
C
Fail to reject H0 because the P-value is greater than = 0.01.
D
Fail to reject H0 because the test statistic is greater than = 0.01.