9. The response time of a computer system to a request for a certain type of information is hypothesized to have an exponential distribution with parameter l  1 [so if X  response time, the pdf of X under H0 is f0(x)  ex for x  0].

a. If you had observed X1, X2, . . . , Xn and wanted to use the chi-squared test with ve class intervals having equal probability under H0, what would be the resulting class intervals?

b. Carry out the chi-squared test using the following data resulting from a random sample of 40 response times:

.10 .99 1.14 1.26 3.24 .12 .26 .80

.79 1.16 1.76 .41 .59 .27 2.22 .66

.71 2.21 .68 .43 .11 .46 .69 .38

.91 .55 .81 2.51 2.77 .16 1.11 .02 2.13 .19 1.21 1.13 2.93 2.14 .34 .44