Suppose we want to assess the effect of a one-day SAT prep class at a 5% level of significance. Scores on the SAT writing exam c
an range from 200 to 800. A random sample of 50 students takes the SAT writing test before and after a prep class. We test the hypotheses: : : where is the mean of the difference in SAT writing scores (after minus before) for all students who take the SAT prep class. The sample mean is 5 with a standard deviation of 18. Since the sample size is large, we are able to conduct the T-Test. The T-test statistic is approximately 1.96 with a P-value of approximately 0.028. What can we conclude
The conclusion is that since the value of 0.028 is less than 0.05 so we reject the null hypothesis at 5% level of significance and conclude that the mean of the difference in SAT writing scores for all students who take SAT prep class is equal to 0.
<h3>What is a null hypothesis?</h3>
A null hypothesis is a hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling error.
Here, the effect of a one-day SAT prep class at a 5% level of significance was assessed. Since the value of 0.028 is less than 0.05 so we reject the null hypothesis at 5% level of significance and conclude that the mean of the difference in SAT writing scores for all students who take SAT prep class is equal to 0.
