# PSY210 Psychological Statistics

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Simply reporting measures of central tendency or measures of variability will not tell the whole story. Using the following information, what else does a psychologist need to know or think about when interpreting this information?
A school psychologist decided to separate some classes by gender to see if learning improved. She looked at student scores on the final exam and obtained the following information: Students in boy-girl classrooms obtained an average of 71.4 on their final exams with a standard deviation of 10.8 whereas students in single-gendered classrooms obtained an average of 75.9 on their final exams with a standard deviation of 8.2. She concludes that the single-gendered classrooms lead to better learning.

• PSY210 Psychological Statistics (?) -

What is your question? You are lacking n for each group.

Z = (mean1 - mean2)/standard error (SE) of difference between means

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√n

If only one SD is provided, you can use just that to determine SEdiff.

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

• PSY210 Psychological Statistics -

what else does a psychologist need to know or think about when interpreting this information?

A school psychologist decided to separate some classes by gender to see if learning improved. She looked at student scores on the final exam and obtained the following information: Students in boy-girl classrooms obtained an average of 71.4 on their final exams with a standard deviation of 10.8 whereas students in single-gendered classrooms obtained an average of 75.9 on their final exams with a standard deviation of 8.2. She concludes that the single-gendered classrooms lead to better learning.