A study was conducted of the effects of a special class desi

A study was conducted of the effects of a special class designed to aid students with verbal skills. Each child was given a verbal skills test twice, both before and after completing a 4-week period in the class. Let Y=score on exam at time2-score on exam at time 1. Hence , if the populations mean

Solution

a. Make a decision using ?=0.05 and Interpret. If the decision in is actually (unknown to us) incorrect, what type of error has been made? What could you do to reduce the chance of that type of error?

Since the p-value is less than 0.05, we reject the null hypothesis. So we can conclude that the effect is positive.

Type I error: We reject the null hypothesis when it is false.

We can increase sample size to reduce the chance of that type of error

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b. True or False? When we make a decision using ?=0.05, this means that if the special class is truly beneficial, there is only a 5% chance that we will conclude that it is not beneficial.

False, there is only a 5% chance that we will conclude that it is beneficial.