statistic assignment 2

PSYC 6036

Statistics Homework - Central Tendency

Note: All of the work can be done by hand. Some of this work can be done SPSS.

1) Find the mean, median, and mode for the following set of scores:

3 6 7 3 9 8 3 7 5

2) One sample of n=12 scores has a mean of M=7 and a second sample of n=8 scores has a mean of M=12. If the two samples are combined, what is the mean of the combined sample?

3) A sample of n=15 scores has a mean of M=8. A new score of 16 is added to the sample. What is the new mean of the sample? And why do you know, without any calculation, that the mean would increase?

4) A sample of n=7 scores has a mean of M=5. After one new score is added to the sample, the new mean is found to be M=6. What is the value of the new score?

5) A student wants to graduate with a GPA of 3.7. A student has taken 30 hours and has a cumulative GPA of 3.6. The student has 12 hours remaining. What GPA over those 12 hours does the student need to get to a GPA of 3.7?

6) Identify the approximate positions of the mean, median, and mode for the following distributions.

A) normal

B) positively skewed

C) rectangular (somewhat of a trick question)

7) Describe a situation in which you would choose to use the following statistic?

A) mean

B) median

C) mode