elementary statistics.doc - 1 Elementary Statistic...

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Elementary Statistic
*Question 6. A psychologist is interested in knowing whether adults who were bullied as
children differ from the general population in terms of their empathy for others. On a
questionnaire designed to measure empathy, the mean score for the general population is 30.6.
Random sampling of 67 scores obtained from individuals who were bullied yielded a mean of
39.5 and a standard deviation of 6.6. (Use these numbers only for this question!)
What are the degrees of freedom? (numeric value only)
*Question 7 . A psychologist is interested in knowing whether adults who were bullied as
children differ from the general population in terms of their empathy for others. On a
questionnaire designed to measure empathy, the mean score for the general population is 40.18.
Random sampling of 141 scores obtained from individuals who were bullied yielded a mean of
82.59 and a standard deviation of 5.01. (Use these numbers only for this question!)
What is the z-value or t-value you obtained (your test statistic)? (numeric value only, including
negative sign if required)
*Question 11. A psychologist is interested in knowing whether adults who were bullied as
children differ from the general population in terms of their empathy for others. On a
questionnaire designed to measure empathy, the mean score for the general population is 72.1.

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Random sampling of 76 scores obtained from individuals who were bullied yielded a mean of
118.08 and a standard deviation of 22.87. (Use these numbers only for this question!)
Calculate the 99% confidence interval.
Question 12. A psychologist is interested in knowing whether adults who were bullied as
children differ from the general population in terms of their empathy for others. On a
questionnaire designed to measure empathy, the mean score for the general population is 30.6.
Random sampling of 25 scores obtained from individuals who were bullied yielded a mean of
39.5 and a standard deviation of 6.6.
Calculate the 99% confidence interval.
Steps:
What is the new critical value you will use for this calculation?
±1.645
±2.064
±2.756

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±2.797
6.74
*Question 13. A psychologist is interested in knowing whether adults who were bullied as
children differ from the general population in terms of their empathy for others. On a
questionnaire designed to measure empathy, the mean score for the general population is 66.88.