Question

Suppose that Rachel studied for the Graduate Management Admission Test (GMAT) using a well-known preparation class...

Suppose that Rachel studied for the Graduate Management Admission Test (GMAT) using a well-known preparation class and was thrilled to receive a total score of 770. Her friend Eric, however, thinks she would have scored just as well without the class. To test the efficacy of the class, they obtain a small but random sample of 19 test results from other students using the same class. This sample's average is 568.56 with a standard deviation of 116.72. In comparison, the national average was 550.12. Assume the population's results are normally distributed but that its standard deviation is not known. Rachel and Eric decide to perform a two-tailed t ‑test at a significance level of α = 0.05 . How many degrees of freedom should they use in their calculations?

df=___

0 0
Add a comment Improve this question Transcribed image text
Answer #1

Solution :

Given that ,

Standard deviation is not known.

n = 19

df = n - 1 = 19 - 1 = 18

Add a comment
Know the answer?
Add Answer to:
Suppose that Rachel studied for the Graduate Management Admission Test (GMAT) using a well-known preparation class...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • The Graduate Management Admission Test (GMAT) is a standardized exam used by many universities as part of the assessment for admission to graduate study In business

    The Graduate Management Admission Test (GMAT) is a standardized exam used by many universities as part of the assessment for admission to graduate study In business. The average GMAT score is 547 (Magoosh website, January 5, 2015). Assume that GMAT scores are bell-shaped with a standard deviation of 100. Make sure to use the empirical rule to answer these questions. a. What percentage of GMAT scores are 647 or higher? b. What percentage of GMAT scores are 747 or higher (to 1...

  • The Graduate Management Admission Test (GMAT) is taken by individuals interested in pursuing graduate manage...

    The Graduate Management Admission Test (GMAT) is taken by individuals interested in pursuing graduate management education. GMAT scores are used as part of the admissions process for more than 6100 graduate management programs worldwide. The mean sore for all test-takers is 550 with a standard deviation of 120 A researcher in the Philippines is concerned about the performance of undergraduates in the Philippines on the GMAT. She believes that the mean scores for this year's college seniors in the Philippines...

  • A standardized test for graduate school admission has a mean score of 151 with a standard...

    A standardized test for graduate school admission has a mean score of 151 with a standard deviation of 10 and a unimodal, symmetric distribution of scores A test preparation organization teaches small classes of 9 students at a time. A larger organization teaches classes of 64 at a time. Both organizations publis the mean scores of all their classes. Complete parts a through c below. a) What would you expect the sampling distribution of mean class scores to be for...

  • this is a single sample t test problem this is math Assignment #11 Single Sample t-Test...

    this is a single sample t test problem this is math Assignment #11 Single Sample t-Test What factor determines whether you should use a z-test or a t-test statistic for a hypothesis test? 11.1 A sample is selected from a population mean of u 30. A treatment is administered to the individuals in the sample and, after treatment, the sample mean found to be M 11.2 = 31.3 with a sample variance of s2 9 If the sample consists of...

  • 6. The t test for two independent samples - One-tailed example using tables Aa Aa Most...

    6. The t test for two independent samples - One-tailed example using tables Aa Aa Most engaged couples expect or at least hope that they will have high levels of marital satisfaction. However, because 54% of first marriages end in divorce, social scientists have begun investigating influences on marital satisfaction. [Data source: This data was obtained from National Center for Health Statistics.] Suppose a counseling psychologist sets out to look at the role of economic hardship in relationship longevity. He...

  • 10. The t test for two independent samples - One-tailed example using tables Most engaged couples...

    10. The t test for two independent samples - One-tailed example using tables Most engaged couples expect or at least hope that they will have high levels of marital satisfaction. However, because 54% of first marriages end in divorce, social scientists have begun investigating influences on marital satisfaction. [Data source: This data was obtained from the National Center for Health Statistics.] Suppose a clinical psychologist sets out to look at the role of sexual orientation in relationship longevity. He decides...

  • 10. The t test for two independent samples - One-tailed example using tables Most engaged couples...

    10. The t test for two independent samples - One-tailed example using tables Most engaged couples expect or at least hope that they will have high levels of marital satisfaction. However, because 54% of first marriages end in divorce, social scientists have begun investigating influences on marital satisfaction. [Data source: This data was obtained from the National Center for Health Statistics.] Suppose a clinical psychologist sets out to look at the role of sexual orientation in relationship longevity. He decides...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT