Exam 24: The Randomized Block Design

True or False: Referring to Table 11-10,the randomized block F test is valid only if the population of crop yields is normally distributed for the 3 varieties.

TABLE 11-11 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 Table 11-11,what is the value of the F test statistic for testing the block effects?

TABLE 11-8 An important factor in selecting database software is the time required for a user to learn how to use the system.To evaluate three potential brands (A,B and C)of database software,a company designed a test involving five different employees.To reduce variability due to differences among employees,each of the five employees is trained on each of the three different brands.The amount of time (in hours)needed to learn each of the three different brands is given below: Below is the Excel output for the randomized block design: -Referring to Table 11-8,what is the critical value for testing the block effects at a 0.05 level of significance?

TABLE 11-8 An important factor in selecting database software is the time required for a user to learn how to use the system.To evaluate three potential brands (A,B and C)of database software,a company designed a test involving five different employees.To reduce variability due to differences among employees,each of the five employees is trained on each of the three different brands.The amount of time (in hours)needed to learn each of the three different brands is given below: Below is the Excel output for the randomized block design: -True or False: Referring to Table 11-8,the randomized block F test is valid only if there is no interaction between the amount of time needed on the 3 brands of software and the 5 employees.

True or False: Referring to Table 11-10,based on the Tukey-Kramer procedure with an overall level of significance of 0.01,the agronomist would decide that there is a significant difference between the crop yield of Smith and Trevor seeds.