Consider the following exponential probability density function. 1 -x/4 f(x) = -e (a) Write the formula for P(x ≤ xo). for x 20 (b) Find P(x ≤ 2). (Round your answer to four decimal places.) (c) Find P(x ≥ 4). (Round your answer to four decimal places.) 0.3679

Let X be the number of visits to the dentist's office for a randomly selected student. Suppose that X has a probability distribution function given by the following table: X P(X= x) 0.15 0.65 Find P(X ≤u) where µ = E(X) is the average number of visits. 0.5 0.15 1 1 0.50 2 0.35

TF.8