A score of 243 is a "basic" reading level.

Question

Scores for a random sample of 3000 students had a xbar = 250 with a standard error 1.0
The 99% confidence interval for the mean score all students in the city is 247.4 to 252.6.

Ques: Is there good evidence that the mean for all students in the city is less than the basic level?

Ans: 243 is not in the 99% confidence level. It is below.
The answer in the back of the book says:"we would fail to reject Ho: u=243 against the one-sided alternative hypothesis Ha: u (less than) 243 at the 1% significance level."

I do not understand the book answer "we would fail to reject..." What does fail to reject mean?

Does this mean there IS good evidence that the mean is less than the basic level? or Not?

Answer 1

Your point is well taken. Sometimes academics tend to write in meaningless, ill-defined phrases. Here, it is clear the hypothesis is rejected.

Answer 2

So there is NOT good evidence, correct?

Answer 3

THERE IS NOT GOOD EVIDENCE