Question

The Internet shows that the mean score on 2014 English Verbal Test is 260, with the standard deviation 55 points. Evergreen High School Principal thinks the test score information is too old and should be updated. He sets up a hypothesis test at significance level Alpha = 0.10 He samples 28 students in year 2020. Their mean score is 278. Part 1: what is the claim? Part 2: what is the critical value? Part 3: what is the test statistic? Part 4: what is the decision? Select one: a. Part 1 H1 μ ≠ 260 Part 2 the critical value(s) is ± 1.645* Part 3 the test-statistic = 1.732 Part 4 there is significant evidence to reject Ho b. Part 1 H1 μ > 260 Part 2 the critical value(s) is 1.703* Part 3 the test-statistic = 1.732 Part 4 there is significant evidence to reject Ho c. Part 1 H1 μ ≠ 278 Part 2 the critical value(s) is ± 1.28* Part 3 the test-statistic = 0.0000 Part 4 the principal fails to reject Ho d. Part 1 H1 μ > 278 Part 2 the critical value(s) is 2.048* Part 3 the test-statistic = 0.047363 Part 4 the principal fails to reject Ho

Answer 1

Null hypothesis;HO: u= 260 Alternative hypothesis;H1: Sample mean: Sample size: Population standard deviation: ut 260 X = 278 given n= 28 given o= 55 given a= 0.1 given za/2 = + 1.645 Z< -1.645 or z> 1.645 Level of significance: Critical values Critical region : Test statistic: X-u 1.732 1.732 p-value: For z= the two tailed p-value is Decision: 0.0833 reject Ho