Two Population Means with Known Standard Deviations · Try It 1

The means of the number of revolutions per minute of two competing engines are to be compared. Thirty engines are randomly assigned to be tested. Both populations have normal distributions. shows the result. Do the data indicate that Engine 2 has higher RPM than Engine 1? Test at a 5 percent level of significance.

$$\begin{array}{ccc}\text{Engine}& \text{Sample Mean Number of RPM}& \text{Population Standard Deviation}\\ \text{1}& \text{1,500}& \text{50}\\ \text{2}& \text{1,600}& \text{60}\end{array}$$

OpenStax, Statistics · §10.2 Two Population Means with Known Standard Deviations · Try It 1