Let us illustrate the idea of a sampling distribution in the case of a very small sample from a very small population. The population is the scores of 10 students on an exam:
Student 0 1 2 3 4 5 6 7 8 9
Score 82 62 80 58 72 73 65 66 74 62
The parameter of interest is the mean score in this population. The sample is an SRS of size n = 4 drawn from the population.
a. Find the mean of the 10 scores in the population. This is the population mean .
b. Use RAND function or StatTools to select 4 students randomly from the file below. What is the mean of the sample scores? This statistic is an estimate of the population mean.
c. Repeat this process 10 times or you can draw 10 samples simultaneously using StatTools. Make a histogram of the 10 values of sample means. You are constructing the sampling distribution of sample means. What is the center of your histogram?
d. Is the center of your histogram close to the population mean?