Question

Elephants sometimes damage trees in Africa. It turns out that elephants dislike bees.

They recognize beehives in areas where they are common and avoid them. Can this

information be used to keep elephants away from trees? Researchers want to design an

experiment to answer these questions using acacia trees and three treatments: active

hives, empty hives, and no hives.

a. Identify the experimental units in this experiment.

b. Explain why it is beneficial to include some trees that have no hives.

c. Describe how the researchers could carry out a completely randomized design for

this experiment. Include a description of how the treatments should be assigned.

Short answer

The answers to these parts is:

a) A response variable is a variable that assesses a study's outcome or result.

b) A total of 24 (unique) trees have been assigned to treatment 1.

c) Those with empty beehives, and those with no beehives.

Step-by-step solution

Part (a) Step 1: Given information

We have to Identify the experimental units in this experimen

Part (a) Step 2: Explanation

The experimental units are the members of the population from whose data was gathered.

EXPERIMENTAL UNITS = $72$ acacia trees chosen at random

Individuals are purposely subjected to a treatment in order to study their reactions in an experiment.

In the tree, place an active, empty, or no beehive.

A response variable is a variable that assesses a study's outcome or result.

DAMAGE CAUSED BY ELEPHANTS = RESPONSE VARIABLE

Part (b) Step 1: Given information

We have to tell that why it is beneficial to include some trees that have no hives

Part (b) Step 2: Explanation

Choose the first of the two-digit numbers. If the number is between $01$and $72$, the matching tree will receive treatment, otherwise on to the next 2-digit number.

Continue until a total of $24$(unique) trees have been assigned to treatment $1$.

Select 24 (unique) trees to get treatment $2$in the same way (trees did not receive treatment 1).

Part (c) Step 1: Given information

We have to tell about how the researchers could carry out a completely randomized design.

Part (c) Step 2: Explanation

Randomly place active beehives in $24$ acacia trees, empty beehives in $24$ acacia trees, and empty beehives in the remaining 24 acacia trees. To accomplish so, give the trees numbers ranging from $01to72$ and pick $24$2-digit numbers from this range using a random number table. The active beehives will be located in such trees. The vacant beehives will be assigned to the trees linked with the next $24$ 2-digit numbers, while the remaining $24$ trees will remain without beehives. Compare the damage caused by elephants to trees with active beehives, empty beehives, and beehives that aren't active.