- A school administrator is planning to switch to a new math program for the 5
th grade. The new
program depends on the abilities of the current 4
th grade students who will enter 5
th grade for
the new program. The administrator randomly selects n=49 4
th graders for ability testing.
Assume that the ability test results in interval data. The sample mean is a score of 27 and σ=21.
Construct 80%, 90%, and 95% confidence intervals for μ. What happens to the size of the
interval as confidence increases? - See example7 (See below) on page 502 of Chapter 21 from Moore and Notz. Find a 99%
confidence interval. - See Exercise 21.30 of Moore & Notz (See Below)
- Use the z-score method to compute the power of the following statistical tests:
a. H0
:μ=17; H1=μ>17; Hs
: μ=23; α=.05; σ=18; n=36
b. Same as a but H1≠μ>17
c. Same as a but σ=36
d. Same as a, but n=144 - Given the following situation, determine the sample sizes needed to obtain a power of .5, .8, and
.95: H0
:μ=75; H1
:μ≠75; Hs
: μ=60; α=.05; σ=30
Sample Solution