Joshua was interested in studying the effect of
exercise on the pulse rates of several of his
friends. Which of the following four-step
procedures would be best for completing this
study?
A. Step 1 Step 2 Step 3 Step 4
Measure
pulse
rates of
friends

Have
friends
run in
place for
2 minutes

Measure
pulse
rates of
friends

Have
friends
sit for
5 minutes

B.
Step 1 Step 2 Step 3 Step 4
Measure
pulse
rates of
friends

Have
friends
run in
place for
2 minutes
Have
friends
sit for
5 minutes

Measure
pulse
rates of
friends

C.
Step 1 Step 2 Step 3 Step 4
Have
friends
sit for
5 minutes

Measure
pulse
rates of
friends

Have
friends
run in
place for
2 minutes

Measure
pulse
rates of
friends

D.
Step 1 Step 2 Step 3 Step 4
Measure
pulse
rates of
friends

Have
friends
sit for
5 minutes
Have
friends
run in
place for
2 minutes

Measure
pulse
rates of
friends