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 120 points. If a sample of 225 students are given the test, what would be the standard error of the mean?

8 is the standard error of mean.                                      

Step-by-step explanation:

We are given the following in the question:

Sample size, n = 225

Standard deviation = 120

We have to find the standard error of he mean.

Standard error is the ration of standard deviation to square root of sample size.

Formula:

Thus, 8 is the standard error of mean.

problem:

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

f(5/2) = 10/3

i hope this !