Every video submission at SmartLearn incurs a base cost of $0.25 for automated review. If the video is automatically approved, it proceeds to manual review, which adds $1.50 to the cost.

a) Write down the formulas for the expected value and variance of review cost per video submission as a function of the random variable auto_approved. 

b) Compute the expected review cost per video submission.

c) Compute the variance of the review cost per video submission.

Note: If you were unable to estimate the probability in the previous question, assume that the probability of automatic approval is 0.76 for this question.