Answer Happy

7. (12 points) Administrators in a large urban district take a random sample of 50 seventh graders, 20 of whom attended pre-school and 30 of whom did not, and tested their pre-algebra achievement levels. They found: . Of the students that attended pre-school, 8 were below grade level, 6 were at grade level, and 6 were advanced. . Of the students that did not attend pre-school, 6 were below grade level, 15 were at grade level, and 9 were advanced. (a) Is the sample size large enough to perform a chi-square test of independence? (b) Perform a chi-squared test of independence (regardless of your answer to (a)) of pre- school attendance and pre-algebra achievement level. (c) Does your result show that pre-school does not affect pre-algebra achievement? Or are there other explanations?