Question

During a test period, an experimental group of 10 vehicles using an 85 percent ethanol-gasoline mixture showed mean CO2 emissions of 240 pounds per 100 miles, with a standard deviation of 20 pounds. A control group of 14 vehicles using regular gasoline showed mean CO2 emissions of 252 pounds per 100 miles with a standard deviation of 15 pounds. A quick comparison of the sample variances suggests that the population variances are

Answer 1

A quick comparison of the sample variances suggests that the population variances are same or almost equal.

Explanation:

The populations from which two samples are drawn are normally distributed.

The variable used to predict another variable is called an independent variable.

F- distribution is used for the test of two sample hypotheses of variances.

If two populations have equal variances then the test Statistic is nearly equal to 1.

t= s²₁/s²₂i

As the variances are almost or nearly equal the test statistic would be almost equal to 1.