Question

The National Assessment of Educational Progress (NAEP) includes a mathematics test for eighth-graders. Scores on the test range from 0 to 500. Suppose that you give the NAEP test to an SRS of 900 eighth-graders from a large population in which the scores have mean μ = 287 and standard deviation σ = 129. The mean x will vary if you take repeated samples.

The sampling distribution of x is approximately Normal. It has mean μ = 287. What is its standard deviation? (Round your answer to three decimal places.)

Answer 1

Solution:

Given that,

mean =   = 287

standard deviation =   = 129

n = 900

= 287

=  ( /n) = (129 / 900 ) = 4.300