1) You want to construct a 92% confidence interval. The correctz* to use is

A) 1.645

B) 1.41

C) 1.75

2) Suppose the average Math SAT score for all students takingthe exam this year is 480 with standard deviation 100. Assume thedistribution of scores is normal. The senator of a particular statenotices that the mean score for students in his state who took theMath SAT is 500. His state recently adopted a new mathematicscurriculum, and he wonders if the improved scores are evidence thatthe new curriculum has been successful. Since over 10,000 studentsin his state took the Math SAT, he can show that the P-value fortesting whether the mean score in his state is more than thenational average of 480 is less than 0.0001. We may correctlyconclude that

A) these results are not good evidence that the new curriculumhas improved Math SAT scores.

B) there is strong statistical evidence that the new curriculumhas improved Math SAT scores in his state.

C) although the results are statistically significant, they arenot practically significant, since an increase of 20 points isfairly small.

3) Suppose the average Math SAT score for all students takingthe exam this year is 480 with standard deviation 100. Assume thedistribution of scores is normal. A SRS of four students isselected and given special training to prepare for the Math SAT.The mean Math SAT score of these students is found to be 560, 80points higher than the national average. We may correctlyconclude

A) the results are statistically significant at level α = 0.05,but they are not practically significant.

B) the results are not statistically significant at level α =0.05, but they are practically significant.

C) the results are neither statistically significant at level α= 0.05 nor practically significant.