Which type of parametric test should you run if you wanted to investigate the effect of antidepressants by giving one group of people an antidepressant and another group of people a placebo? a. One-sample t-test
b. z-test
c. Related-samples t-test
d. Independent-samples t-test

d. Independent-samples t-test

Step-by-step explanation:

The independent samples t-test can be described as a test under which two groups are compared on the mean value of a continuous normally distributed variable.

The independent samples t-test model is based on the assumption that the mean score of the dependent variable is different because the of the impact of the independent variable that differentiates the two groups.

The independent-samples t-test is also known as a parametric test in which the means of two independent groups are compared with the aim of ascertaining if there is statistical evidence that the associated population means are significantly different.

In this question, there are two independent groups which we intend to compare in order to investigate the effect of antidepressants. The first group is the group of people given antidepressant, while the second is another group of people that is given a placebo. This is a perfect example of independent-samples t-test.

Therefore, the correct option is d. Independent-samples t-test. That is, the type of parametric test that should be run in order to investigate the effect of antidepressants by giving one group of people an antidepressant and another group of people a placebo.

3 days

Step-by-step explanation:

He feeds his dog 1 1/2 every day so after 2 days he has fed the dog 3 cups of food and on day three he feeds the dog another 1 1/2 to give you a total of 4 1/2. Or to put is faster 1 1/2 times 3 equals 4 1/2.