A scientist is conducting a study on the effect of eating chocolate and overall mood. They believe that gender is a significant factor. The participants are divided by gender. Then, within each group, participants are randomly assigned to consume either chocolate or a placebo and then rate their mood for the day. This experiment will run for two weeks. Which type of experimental design does this situation describe? A. Randomized Block Design.
B. Matched-Pair Design.
C. Case-Control Design.
D. Completely Randomized Design.

The correct option is;

A. Randomized block design

Step-by-step explanation:

A randomized block design is one where the sample or subjects of the experiment are split into groups called blocks of experimental units where the variation in each block is lower than the variation among or between blocks, such that variation is controlled. In a random order, the treatments are performed on each experimental of the blocks.

In the question, the experimental units are grouped by gender and the treatment (consumption of chocolate or placebo) is randomly administered to the experimental units.

1. 34

2. 268

3. x=14.4

step-by-step explanation: