Question 2 (1 point) A listening test was administered to Spanish teachers before and after an institute designed to improve Spanish listening skills. The following random samples of listening scores for 10 Spanish teachers are obtained. No. 1 2 3 4 5 6 7 8 9 10 Pre 30 28 26 15 31 20 31 29 Post 34 28 29 30 30 18 34 27 32 32 31 33 Determine if the institute improved listening skills at the 2.5% significance level. Let /p be the mean improvement in listening scores for teachers attending the institute (Post -Pre). What is the null hypothesis? OND