If a sample of 77 students is taken from a population of 950 students, the population variance, [tex]$\sigma^2$[/tex], is the variance of how many students' heights?

A. 77
B. Both 77 and 950
C. 950
D. Neither 77 nor 950



Answer :

To answer this question, we need to carefully understand the differences between sample variance and population variance.

1. Population Variance:
- Population variance (denoted as [tex]\(\sigma^2\)[/tex]) is a measure that describes the spread of the entire population's data points. In this case, it pertains to all 950 students.

2. Sample Variance:
- Sample variance is calculated from a subset or sample of the population data (in this scenario, 77 students), and it serves as an estimate of the population variance.

Given the context:

- Population variance relates to the entire population, which is all 950 students, not just the sample of 77 students.
- The problem specifies that we are interested in the population variance, [tex]\(\sigma^2\)[/tex], which inherently is a parameter for the entire population.

Based on this understanding, the correct answer is:

C. 950

This means the population variance [tex]\(\sigma^2\)[/tex] is the variance of the heights of all 950 students, not the sample of 77 students.