An elementary school started a special reading enrichment
program for seventh-graders that has been underway for eight
months. One of the investigators wants to confirm the program is
having its intended effect, and collects a sample of 34 students
from the program with a standardized reading test average of 24.1.
The standardized reading test average for seventh-graders in the
country is 26.1 with a standard deviation of 4.9. What can the
investigator conclude with α = 0.01?
Population:
the school
seventh-graders in the program
the program months
seventh-graders in the country
Sample
the school
seventh-graders in the program
the program months
seventh-graders in the country
Compute the appropriate test statistic(s) to make a decision
about H0.
critical value =
If appropriate, compute the CI. If not appropriate, input "na"
for both spaces below.
[ , ]
e) Compute the corresponding effect size(s) and
indicate magnitude(s).
If not appropriate, input and select "na" below.
d = ; ---Select--- na trivial effect
small effect medium effect large effect
r2 = ; ---Select--- na
trivial effect small effect medium effect large effect
Ans:
population is seventh-graders in the country
sample is seventh-graders in the program
Test statistic:
z=(24.1-26.1)/(4.9/SQRT(34))
z=-2.38
critical z values=+/-2.576
99% confidence interval for mean
=24.1+/-2.576*(4.9/sqrt(34))
=24.1+/-2.165
=(21.935, 26.265)
e) d and r^2 are not applicable for z statistic
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