Answer :
Answer:
a) mean = u = 83
b) Your friend's score is 1.625 standard deviations below the mean
Step-by-step explanation:
Note:
- The correct question is as follows:
" In the Social Psychology course, you receive a score of 77 on the second exam. You are told that the standard deviation of the second exam is 8 and that your score is .75 standard deviations below the mean. "
Find:
a.What is the class mean of the second exam?
b.Your friend scored a 70 on the second exam. How many standard deviations below the mean is your friend’s score?
Solution:
- The class mean can be calculated by using the given data of your score being 0.75 standard deviation less than mean:
Your score = mean - 0.75*standard deviation.
- Plug in the values:
77 = mean - 0.75*8
mean = u = 83
- Now your friend has a score of 70 on second exam, using the above relation again we have:
Friend's score = mean - a*standard deviation.
Where, a is the constant to be found:
70 = 83 - a*8
a = (70 - 83 ) / -8
a = 1.625
- Your friend's score is 1.625 standard deviations below the mean
