Question

A group of 67 randomly selected students have a mean score of 31.3 with a standard deviation of 5.3 on a placement test. What is the 90% confidence interval for the mean score of all students taking the test? 30.2 < 32.4 30.2 < р < 32.4 33.02 H1 < 35.04 33.02 < р < 35.04

Answer 1

Solution Given , n=67 - 31.3 Sa = 5.3 we Lince we have given Sample standard deviations Cund apply t-test. 90% confidence intewal for t-test. store X I where X= 0.10 XAN 37/6 tar = 1.668 (by using t-table) Now, (31.3 I 1.668 x 5:3) 67 3) (31.3 † 1:08) (30.22 9 32:38) =) ( 30.2, 32.4) Hence, (30.2 <ll< 32.4) option is conect