A website experiences traffic during normal hours at a rate of 12 visits per hour. Assume that the duration between visits has the exponential distribution.

a. Find the probability that the duration between two successive visits to the web site is more than ten minutes. choose your answer from the following:

a) 0.5654 b) 0.1353 c) 0.8647 d) 0.7576 e) 0.4346

b. The top 25% of durations between visits are at least how long? choose your answer from the following:

a) about 6min 56 sec b) about 6 hrs 26 min c) about 1 min 26 sec d) about 1 hr 51 min e) about 2 min 9 sec

c. Suppose that 20 minutes have passed since the last visit to the web site. What is the probability that the next visit will occur within the next 5 minutes? choose your answer from the following:

a) 0.3679 b) 0.0392 c) 0.9608 d) 0.9093 e) 0.6321

d. Find the probability that less than 7 visits occur within a one-hour period. choose your answer from the following:

a) 0.9542 b) 0.0437 c) 0.0458 d) 0.0895 e)0.9105