An examination was given to two classes of 40 and 50 students. In the first class the mean grade was 74 with standard deviation 8; in the second, mean 78 with standard deviation 7. On a two-tailed test, is there a significant difference between the performance of the two classes at 5% and 1%? (Two-tailed 5% critical value ; 1% critical value .)
Tap an option to check your answer.
Checking your account…
An examination was given to two classes of 40 and 50 students. In the first class the mean grade was 74 with standard deviation 8; in the second, mean 78 with standard deviation 7. On a two-tailed test, is there a significant difference between the performance of the two classes at 5% and 1%? (Two-tailed 5% critical value ± 1.96; 1% critical value ± 2.58 .) (A) There is no significant difference at the 5% and 1% levels of significance. (B) There is a significant difference at the 5% level but no significant difference at the 1% level of significance. (C) There is a significant difference at the 1% level but no significant difference at the 5% level of significance. (D) There is a significant difference in performance at both the 5% and 1% levels.
Also written as: An examination was given to two classes of 40 and 50 students. In the first class the mean grade was 74 with standard deviation 8; in the second, mean 78 with standard deviation 7. On a two-tailed test, is there a significant difference between the performance of the two classes at 5% and 1%? (Two-tailed 5% critical value +/- 1.96; 1% critical value +/- 2.58 .)
Hypothesis testing has come up 47 times in 7 exams since 2007.
This question is on Tests for means, proportions and variances, part of Hypothesis testing in Statistics.
Applying z, t, F and chi-square tests to common problems.
TestStop has 15 past-paper questions on this subtopic.
Question from the DSE 2007 paper. Solutions are TestStop's own. Not affiliated with or endorsed by any examination authority.