statistics

posted by .

To test the hypothesis that students who finish an exam first get better grades, Professor Hardtack
kept track of the order in which papers were handed in. The first 25 papers showed a mean score of
77.1 with a standard deviation of 19.6, while the last 24 papers handed in showed a mean score of
69.3 with a standard deviation of 24.9. Is this a significant difference at á = .05? (a) State the
hypotheses for a right-tailed test. (b) Obtain a test statistic and p-value assuming equal variances.
Interpret these results. (c) Is the difference in mean scores large enough to be important? (d) Is it reasonable
to assume equal variances? (e) Carry out a formal test for equal variances at á = .05, showing
all steps clearly.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. statistics

    For a particular sample of 50 scores on a psychology exam, the following results were obtained. Mean = 78 Midrange = 72 Third quartile = 94 Mode = 84 Median = 80 Standard deviation = 11 Range = 52 First quartile=68 What score was earned …
  2. Statistics

    In Professor Smith's statistics course, the correlation between students' total scores before the final exam and their final exam scores is r = 0.67. The pre-exam totals for all students in the course have a mean of 275 and a standard …
  3. Statistics

    Students were given an exam with 300 multiple-choice questions. The distribution of the scores was normal and mean was 195 with a standard deviation of 30. What were the scores of the students who were within one standard deviation …
  4. statistics

    a study of 40 professors showed they spent on average 13.6 minutes correcting a student papers. Given a standard deviation of 17, the 90% confidence interval of the mean time for all the test papers is what?
  5. res/342

    To test the hypothesis that students who finish an exam first get better grades, Professor Hardtack kept track of the order in which papers were handed in. The first 25 papers showed a mean score of 77.1 with a standard deviation of …
  6. statistics

    SAT Exam Scores – A school administrator wonders if students whose first language is not English score differently on the math portion of the SAT exam than students whose first language is English. The mean SAT math score of students …
  7. UOP

    o test the hypothesis that students who finish an exam first get better grades, Professor Hardtack kept track of the order in which papers were handed in. The first 25 papers showed a mean score of 77.1 with a standard deviation of …
  8. social science statistics

    a professor was curious to whether the students in a very large class she was teaching who turned in their first scored differently from the overall mean on the test.The overall mean score on the test was 75 with a standard deviation …
  9. graduate statistics

    A nursing professor was curious as to whether the students in a very large class she was teaching who turned in their tests first scored differently from the overall mean on the test. The overall mean score on the test was 75 with …
  10. math

    Jenny must sit four papers for an exam. The mean of the first three papers Jenny has sat is 72%. (a)If she wants to get an overall mean of at least 75%,what is the lowest mark she can get in her fourth paper?

More Similar Questions