A teacher gives a third grade class of n = 16 a reading skills test at the beginning of the school year. To evaluate the changes that occur during the year, students are tested again at the end of the year. Their test scores revealed an average improvement of MD = 4.7 points. a. If the variance for the difference scores is s2 = 144, are the results sufficient to conclude that there is significant improvement? Use a one-tailed test with a = 05. b. Compute Cohen's d to measure the size of the reading innovation effect on students' test scores. Show all steps for full credit. You may upload an attachment with your answers. Paragraph B A/ Lato (Recom... 19px (/> C n= 16 Mean= 4.7 Variance =144