Question

a researcher wants to investigate whether there is a difference in the aerobic capacity between two different exercise programs. group 1 participates in a running program, and group 2 participates in a cycling program. after 8 weeks, the aerobic capacity is measured for both groups. below are the sample data:
group 1 (running program): sample size $(n_1)=3$, sample mean $(\overline{x}_1)=40$, sample variance $(s_1^2)=4$
group 2 (cycling program): sample size $(n_2)=4$, sample mean $(\overline{x}_2)=45$, sample variance $(s_2^2)=9$.
question 1:
what is the independent variable in this example?
aerobic capacity
exercise programs (running vs cycling)
sample size
sample variance

Explanation:

An independent variable is what the researcher manipulates. Here, the researcher assigns participants to either running or cycling programs. Aerobic capacity is the dependent variable (what's measured). Sample size and variance are just data - related aspects, not variables being manipulated.

Answer:

Exercise programs (Running vs Cycling)