SCENARIO 11-7 A student team in a business statistics course designed an experiment to investigate whether the brand of bubblegum used affected the size of bubbles they could blow.To reduce the person-to- person variability, the students decided to use a randomized block design using themselves as blocks. Four brands of bubblegum were tested.A student chewed two pieces of a brand of gum and then blew a bubble, attempting to make it as big as possible.Another student measured the diameter of the bubble at its biggest point.The following table gives the diameters of the bubbles (in inches)for the 16 observations.
-Referring to Scenario 11-7, the randomized block F test is valid only if the population of diameters has the same variance for the 4 brands.

Question

SCENARIO 11-7 A student team in a business statistics course designed an experiment to investigate whether the brand of bubblegum used affected the size of bubbles they could blow.To reduce the person-to- person variability, the students decided to use a randomized block design using themselves as blocks. Four brands of bubblegum were tested.A student chewed two pieces of a brand of gum and then blew a bubble, attempting to make it as big as possible.Another student measured the diameter of the bubble at its biggest point.The following table gives the diameters of the bubbles (in inches)for the 16 observations. 
-Referring to Scenario 11-7, the randomized block F test is valid only if the population of diameters has the same variance for the 4 brands.

Quizplus · Accepted Answer

The randomized block F test assumes that the populations have the same variance within each block (in this case, each student who chewed the gum). Therefore, in order for the test to be valid, the population of diameters must have the same variance for each brand of gum. The randomized block F test assumes that the variances of the populations being compared are equal. Therefore, in order for the test to be valid, the population of diameters for the 4 brands must have the same variance.

SCENARIO 11-7 a Student Team in a Business Statistics Course