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?

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 is the standard error of the mean

is the standard deviation

n is the sample size.

Given;

On substitution into the formula we have;

X ≈ 7.56

b

step-by-step explanation:

b

wholesale price is the initial price before markup. retail price comes after the markup.

a price of 8 bucks that's marked up by 100%   is

formula: initial price + (percent markup in fraction/decimal)(initial price)

8+(1)(8)

8+8

16

retail price is $16.