The Scores of a Certain Population on the Wechsler Intelligence

Multiple Choice

The scores of a certain population on the Wechsler Intelligence Scale for Children IV (WISC IV) are thought to be Normally distributed, with mean μ and standard deviation σ= 15. Bill is a child psychologist who obtains a simple random sample of 25 children from this population; each child is given the WISC IV. Bill wishes to test whether the mean for this population differs from the national average of 95, so he uses the hypotheses H₀: = 95 and H_a: μ=95, based on an SRS of size 25 from the population. Bill then calculates a μ≠95% confidence interval for μ and finds it to be 98.42 to 110.20. What should he conclude?

A) He would reject H₀ at the 0.05 level.
B) He would reject H_a at the 0.05 level.
C) He would fail to reject H₀ at the 0.05 level.
D) A mistake has almost certainly been made; the confidence interval must contain μ= 100 at least 95% of the time.