Question

Based upon extensive data from a national high school educational testing​ program, the standard deviation of national test scores for mathematics was found to be 121 points. If a sample of 256 students are given the​ test, what would be the standard error of the​ mean?

Answer 1

Answer:

The standard error of the mean is 7.56

Step-by-step explanation:

The standard error of the mean is defined as the ratio of standard deviation to the square root of the sample size of a data. The standard error of the mean is mathematically expressed as shown below;

$X = \frac{\sigma}{\sqrt{n} }$

X is the standard error of the mean

$\sigma$ is the standard deviation

n is the sample size.

Given;

$\sigma = 121\\n = 256$

On substitution into the formula we have;

$X = \frac{121}{\sqrt{256} }$

$X = \frac{121}{16} }$

X ≈ 7.56