Chapter 6.1, Problem 6.12E

(a)

To determine

To assign ten rats to Dirt A using table B and repeat it four times and write four groups assigned to Diet A.

Answer to Problem 6.12E

  $\text{Group 1: }18,06,08,00,12,04,11,19,02,17.$

  $\begin{array}{l}\text{Group 2: }16,04,19,07,10,13,15,05,09,08.\\ \text{Group 3: }05,16,17,19,00,04,13,02,07,18.\\ \text{Group 4: }12,13,04,18,19,00,16,02,08,17.\end{array}$

Explanation of Solution

  $\begin{array}{l}\text{The rats are labeled 00,01,02,}\mathrm{....}\text{,19}\text{.}\\ \text{We will start at line 110 in Table B}\text{.}\\ \text{Select the first 2-digit number}\text{. If the number is between 01 and 19, then}\\ \text{the corresponding rats are selected for Diet A, else we ignore }\\ \text{the number and select the next 2-digit number}\text{. Repeat until 10 unique rats are }\\ \text{selected for Diet A}\text{.}\\ \text{Group 1: }18,06,08,00,12,04,11,19,02,17.\\ \text{Similarly, select the other three groups of 10 rats out of the remaining 20 rats}\\ \text{starting from line 120,130 and 140 in table B;}\\ \text{Group 2: }16,04,19,07,10,13,15,05,09,08.\\ \text{Group 3: }05,16,17,19,00,04,13,02,07,18.\\ \text{Group 4: }12,13,04,18,19,00,16,02,08,17.\end{array}$

(b)

To determine

To find out how many rats are there in each group of Diet A generated and also what is the average number of Strain one rats assigned to Diet A.

Answer to Problem 6.12E

Average is: $=5.75$ .

  $\begin{array}{l}\text{we see that group 1 contains 7 Strain 1 rats, group 2 contains 4 Strain 1 rats, group 3}\\ \text{contains 5 Strain 1 rats and group 4 contains 7 Strain 1 rats}\text{.}\end{array}$

Explanation of Solution

The even numbered rats are Strain one rats.

Therefore,

  $\begin{array}{l}\text{we see that group 1 contains 7 Strain 1 rats, group 2 contains 4 Strain 1 rats, group 3}\\ \text{contains 5 Strain 1 rats and group 4 contains 7 Strain 1 rats}\text{.}\end{array}$

The average mean is as follows:

  $\begin{array}{l}\overline{x}=\frac{7+4+5+7}{4}\\ =\frac{23}{4}\\ =5.75\end{array}$