16. Probability & Calculus

Which of the following is a discrete random variable?

Which of the following is a continuous random variable?

Find the cumulative distribution function for the probability density function $f\left(x\right)=\frac{3}{8}{(x-1)}^2$ on the interval $[1,3]$. Use the CDF to find the probability that $X$ is between $2$ and $2.5$.