Suppose your statistics instructor gave six examinations dur
Suppose your statistics instructor gave six examinations during the semester. You received the following grades (percent correct): 83, 76, 82, 84, 89, and 73. Instead of averaging the six scores, the instructor indicated he would randomly select three grades and compute the final percent correct based on the three percents.
a. How many different samples, without replacement, of three test grades are possible?
c. Compute the mean of the sample means and compare it to the population mean. (Round your answers to 3 decimal places.) the mean of the sample is? population mean is?
Solution
a)the number of samples is 6C3 = 20
c) you can see the differents but a big number of samples have the same mean 81
| 83 | if I chose a sample | |||
| 76 | 83 | 76 | 84 | 82 |
| 82 | 76 | 82 | 89 | 84 |
| 84 | 82 | 84 | 73 | 89 |
| 89 | ||||
| 73 | ||||
| 81.1666667 | 80.3333333 | 80.66666667 | 82 | 85 |
