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In: Statistics and Probability

Score on a 100-point test is normally distributed with mean 87.7.   You took a sample of...

  1. Score on a 100-point test is normally distributed with mean 87.7.   You took a sample of 36 students. The mean for this group is 92 and the standard deviation is 15.              
    1. Test the hypothesis that the performance of this group is different than the regular student population. Use α=.05.
  • What is the alternative hypothesis?
  • What is the value of the test statistic?
  • would you use the t test?
  • What is the rejection region?
  • the decision is to not reject the null hypothesis. Yes or No?
    1. Test the hypothesis that the performance of this group is better than the regular student population, i.e., their score is greater than the normal population. Use α=.05
  • What is the alternative hypothesis?
  • What is the rejection region?
  • the decision is to not reject the null hypothesis. Yes or No?
  • the 95% confidence interval for the population mean is?
  1. Score on a 20-point assignment is normally distributed with a mean of 15 and standard deviation of 5. You believe that your friends are smarter and that their average is greater. You took a sample of 9 of your friends. The mean for this group is 18.  
  • What is the rejection region?
  • Would you use the t test?
  • The 95% confidence interval for the population mean is

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orchestra answered 2 years ago
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