Question

The National Assessment of Educational Progress (NAEP) includes a mathematical test for eighth?grade students. Scores on the test range from 0 to 500 . Suppose that you give the NAEP test to an SRS of 1000 eighth?graders from a large population in which the scores have mean 299 and standard deviation 116 . The mean x ¯ will vary if you take repeated samples.

The sampling distribution of x ¯ is approximately Normal. It has mean 299 . What is its standard devation? (Enter your answer rounded to three decimal places.)

?=

Answer 1

Solution :

Given that,

mean = = 299

standard deviation = = 116

n = 1000

The sampling distribution of mean and standard deviation is ,

= 299 and

= / n = 116 / 1000 = 3.668