The time, t, between calls (in seconds) on the busiest day of the month for the customer service department at Friendly Bank can be approximated by an exponential distribution with p = 70. (a) Give the probability density function for this distribution. m = [:1 (b) Determine the standard deviation. :1 (c) Find the probability (not percentage] that the time between calls is no more than 47 seconds. Round your answer to four decimal places as needed. :1 (d) Find the probability (not percentage) that the time between calls is 436 seconds or more. Round your answer to four decimal places as needed. D Addka