Suppose the lifetime (in months) of a certain type of lightbulb is a random variable X with pdf f (x) = 23 , x > 1. x2 x a. Find the cdf F(x). b. Find the probability that a lightbulb of this kind lasts longer than 2 months. c. Find the mean and variance of X. d. In a random sample of 5 such lightbulbs, what is the probability that at least 2 of them will work for more than 2 months?

Someone answer asap for ! the boiling point of water at an elevation of 0 feet is 212 degrees fahrenheit (°f). for every 1,000 feet of increase in elevation, the boiling point of water decreases by about 2°f. which of the following represents this relationship if b is the boiling point of water at an elevation of e thousand feet? a. e = 2b - 212 b. b = 2e - 212 c. e = -2b + 212 d. b = -2e + 212

See attachment below and find the equivalent of tan(∠qsr)

What is the missing reason in the proof? segment addition congruent segments theorem transitive property of equality subtraction property of equality?