Post a New Question

Statistics

posted by .

Suppose that the average grade for all people who take this course in statistics is 83 with a standard deviation of 3.5. If your particular class has an average of 89, can you conclude that your class is better than average at the 90 percent confidence level? Sample size 21.

Identify one or two-tailed
States the Null and Alternative Hypothesis
States the Level of Significance
Calculates Test Statistic
Formulates Decision Rule
Makes a Conclusion

  • Statistics -

    Null hypothesis:
    Ho: µ = 83 -->meaning: population mean is equal to 83
    Ha: µ does not equal 83 -->meaning: population does not equal 83

    Since the problem is using confidence intervals, remember that 5% (or .05) will be below the interval and 5% (or .05) will be above the interval. This will be a two-tailed test.

    Using the z-test formula to find the test statistic:
    z = (sample mean - population mean)/(standard deviation divided by the square root of the sample size)
    z = (89 - 83)/(3.5/√21)
    Finish the calculation.

    Determine whether or not to reject the null. If you reject the null, you will conclude a difference.

    I hope this will help get you started.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. AP Statistics

    Maria and Zoe are taking Biology 105 but are in different classes. Maria's class has an average of 78% with a standard deviation of 5% on the midterm, whereas Zoe's class has an average of 83% with a standard deviation of 12%. Assume …
  2. Statistics

    Maria and Zoe are taking Biology 105 but are in different classes. Maria's class has an average of 78% with a standard deviation of 5% on the midterm, whereas Zoe's class has an average of 83% with a standard deviation of 12%. Assume …
  3. Statistics

    Suppose that the average grade for all people who take this course in statistics is 83 with a standard deviation of 3.5. If your particular class has an average of 89, can you conclude that your class is better than average at the …
  4. Hypothesis

    Suppose that the average grade for all people who take this course in statistics is 83 with a standard deviation of 3.5. If your particular class has an average of 89, can you conclude that your class is better than average at the …
  5. Statistics 250

    Final averages are typically approximately normally distributed with a mean of 65 and a standard deviation of 8. Your professor says that the top 10% of the class will receive an A; the next 20%, a B; the next 41%, a C; the next 19%, …
  6. Statistics

    Suppose that the average grade for all people who take this course in statistics is 83 with a standard deviation of 3.5. If your particular class has an average of 89, can you conclude that your class is better than average at the …
  7. stats

    Relatively speaking, which statistics exam did you do better on?
  8. Statistics

    Suppose that the average weight of students in a statistics class is 75.5 kilograms with a standard deviation of 10.3 kilograms. A. 45% of the student weights are above ____ kilograms?
  9. Statistics

    Suppose that the average weight of students in a statistics class is 75.5 kilograms with a standard deviation of 10.3 kilograms. A. 45% of the student weights are above ____ kilograms?
  10. Statistics

    A student wants to test her hypothesis she gives each of her students an IO test. She finds that the average IQ score is 115 and the standard deviation for the class is 30. There are 22 students in the class. She also knows that the …

More Similar Questions

Post a New Question