Question

1. Vitamin D is needed for the body to use calcium. An experiment is designed to study the effects of calcium and vitamin D supplements on the bones of first-year college students. The outcome measure is the total body bone mineral content (TBBMC), a measure of bone health. Two doses of calcium will be used: 0 and 200 milligrams per day (mg/day). The doses of vitamin D will be 0 and 100 international units (IU) per day. The calcium and vitamin D will be given in a single tablet. Subjects for the study will be 24 first-year college students.

(a) What are the factors and the treatments for this experiment? List all possible treatments.

(b) Draw a picture explaining how you would do a randomized experiment with the 24 college students and possible treatments.

(c) Use Rstudio to carry out the randomization. (Follow the examples above).

(d) Is there a placebo in this experiment? Explain your answer.

Answer 1

a)

Factor is an independent variable here factors are Calcium and Vitamin D

Combinations of factor levels are called treatments

Here possible treatment are given below

Here are total four possible treatment (Vitamin D,Calcium)=(0,0),(0,200),(100,0),(100,200)

		Calcium
		0 mg	200 mg
Vitamin D	0 mg	Treatment 1	Treatment 2
	100 mg	Treatment 3	Treatment 4

b)

Way to randomize the experiment with 24 students is that

Put 24 numbers in the hat and have each person draw a number

The number will then correspond to the what type of treatment they will receive

d)

Yes there is placebo in the experiment

because we are giving 0 calcium and 0 vitamin D tablets and the subjects would not know ,

this is a placebo effect where the subject thinks that it is consuming calcium and Vit D tablets where in fact they are not consuming any.

c) not having any idea