Which of the following is a geometric sequence?
a. 1, 1, 2, 3, 5,
b. 1, 1/2, 1/4, 1/8,
c. 7, 4, 1, -2,
d. 2, 4, 6, 8,

The length of time it takes to find a parking space at 9 a. m. follows a normal distribution with a mean of 5 minutes and a standard deviation of 2 minutes. find the probability that it takes at least 8 minutes to find a parking space. (round your answer to four decimal places.)