Question: A school administrator is interested in purchasing a set of teaching aids to supplement classroom instruction. However, before purchasing the aids she wants to make sure student scores on a national standardized test would increase to at least a mean of 85. To asses this, she had 20 students use the teaching aids and recorded their scores (given below). On the basis of this research, would she be justified in purchasing the instructional aids? Use alpha = .05 and show all 4 steps of our hypothesis testing procedure. Interpret your results as if you are addressing a group of other administrators.
Test scores: 82,93,88,98,84,89,90,100,110,79,95,105,91,85,89,86,99,78,97,115