2. In Pennsylvania, students take the Algebra 1 Keystone exams. If a student scores a 1500...

2. In Pennsylvania, students take the Algebra 1 Keystone exams. If a student scores a 1500 the student earns a Proficient Rating. One teacher claims that his students score above Proficient. In a random sample of 80 students, the mean score was 1505with a standard deviation of 25.578.

a. Is there convincing evidence at the ?=0.05level that his students score above Proficient?(show all four steps)

b. Construct a 90% confidence interval for the meancompletion time of all students who took the exam.(show the math and make the conclusion)

c. How many students would have to be sampled to report a margin of error of 5 points?

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orchestra answered 1 year ago

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