The Standard Deviation of the Population of Elementary School Math-

Short Answer

The standard deviation of the population of elementary school math- achievement scores is 7.78. A random sample of 20 elementary school children was selected and yielded a mean achievement score of 80.04.
a. Calculate the standard error of the mean.
b. Use the z test to establish whether this sample could be representative of the general population of elementary school children whose mean math achievement score is known to be 78.00.