a random sample of the grade of 78 students is taken. what is the probability that the average grade will be between 80.3% and 82.3%?

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1. Need a measure of central tendency (mean) and a measure of variability (standard deviation).

Z = (score-mean)/SD

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

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posted by PsyDAG

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