A teacher gives a reading skills test to a third-grade class of n = 25 at the beginning of the

school year. To evaluate the changes that occur during the year, students are tested again
at the end of the year. Their test scores showed an average improvement of MD = 12.7
points with s2
= 100.

State the null hypothesis.
b. Compute the necessary hypothesis test using a two-tailed test with  = .05. Show
your calculations.
c. Make a decision about your null hypothesis. (Include the critical value you used to
base your decision.)
d. Write an APA format statement summarizing your findings (include a measure of
effect size if necessary.)

1 answer

Z = MD/SEm

SEm = SD/√n

Online "^" is used to indicate an exponent, e.g., x^2 = x squared.

SD = √s^2

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.

You can take it from there.