A researcher would like to evaluate the effect of a new read…

A researcher would like to evaluate the effect of a new reading program for second-grade students. She has half of the second-grade students use the new reading program for the first half of the school year and use the current reading program for the second half of the year. The other half of the second-grade students use the current reading program for the first half of the school year and use the new reading program for the second half of the year. The researcher plans to use the data from this study to test whether the new program has had a significant effect on reading scores. Which of the following hypothesis tests would be appropriate?