A Psychologist Has Designed a New Intelligence Test

Multiple Choice

A psychologist has designed a new intelligence test. Historically, time to complete the old test was an average of 120 minutes. With the altered format of the test, the psychologist claims that the time to complete the test is no longer 120 minutes. A sample of 50 new test taking times yielded an average time of 118 minutes. The population standard deviation is known to be 5 minutes
-The null and alternative hypothesis to test if the average time to complete the test had changed from 120 minutes is _____.

A) H₀: µ = 120 H_a: µ ≠ 120
B) H₀: µ ≥ 120 H_a: µ < 120
C) H₀: µ ≤ 120 H_a: µ > 120
D) H₀: µ ≠ 120 H_a: µ = 120
E) H₀: µ ≥ 118 H_a: µ < 118