The response time of a computer system to a request for a ce
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 lamda=1 sec (so if X= response time, the pdf of X under Ho is f0(x)=e^(–x) for x>= 0.
a. If you had observed X1,X2,...,Xn and wanted to use the chi-squared test with five class intervals having equal probability under H0, what would be the resulting class intervals?
b. Carry out the chi-squared test using the follow- ing data resulting from a random sample of 40 response times: .10 .99 1.14 .79 1.16 1.76 .71 2.21 .68 .91 .55 .81 1.26 3.24 .12 .26 .80 .41 .59 .27 2.22 .66 .43 .11 .46 .69 .38 2.51 2.77 .16 1.1 1 .02 2.13 .19 1.21 1.13 2.93 2.14 .34 .44
Solution
Sol)
Chisqaure
Chisqaure value= sum of ((Oi-Ei)2 /Ei)
=92.577
| Oi | Ei | (oi-Ei) | (Oi-Ei)^2 | (Oi-Ei)^2 /Ei |
| 10.99 | 1.33 | 9.66 | 93.3156 | 70.16211 |
| 1.14 | 1.33 | -0.19 | 0.0361 | 0.027143 |
| 0.79 | 1.33 | -0.54 | 0.2916 | 0.219248 |
| 1.16 | 1.33 | -0.17 | 0.0289 | 0.021729 |
| 1.76 | 1.33 | 0.43 | 0.1849 | 0.139023 |
| 0.71 | 1.33 | -0.62 | 0.3844 | 0.289023 |
| 2.21 | 1.33 | 0.88 | 0.7744 | 0.582256 |
| 0.68 | 1.33 | -0.65 | 0.4225 | 0.317669 |
| 0.91 | 1.33 | -0.42 | 0.1764 | 0.132632 |
| 0.55 | 1.33 | -0.78 | 0.6084 | 0.457444 |
| 0.81 | 1.33 | -0.52 | 0.2704 | 0.203308 |
| 1.26 | 1.33 | -0.07 | 0.0049 | 0.003684 |
| 3.24 | 1.33 | 1.91 | 3.6481 | 2.742932 |
| 0.12 | 1.33 | -1.21 | 1.4641 | 1.100827 |
| 0.26 | 1.33 | -1.07 | 1.1449 | 0.860827 |
| 0.8 | 1.33 | -0.53 | 0.2809 | 0.211203 |
| 0.41 | 1.33 | -0.92 | 0.8464 | 0.636391 |
| 0.59 | 1.33 | -0.74 | 0.5476 | 0.411729 |
| 0.27 | 1.33 | -1.06 | 1.1236 | 0.844812 |
| 2.22 | 1.33 | 0.89 | 0.7921 | 0.595564 |
| 0.66 | 1.33 | -0.67 | 0.4489 | 0.337519 |
| 0.43 | 1.33 | -0.9 | 0.81 | 0.609023 |
| 0.11 | 1.33 | -1.22 | 1.4884 | 1.119098 |
| 0.46 | 1.33 | -0.87 | 0.7569 | 0.569098 |
| 0.69 | 1.33 | -0.64 | 0.4096 | 0.30797 |
| 0.38 | 1.33 | -0.95 | 0.9025 | 0.678571 |
| 2.51 | 1.33 | 1.18 | 1.3924 | 1.046917 |
| 2.77 | 1.33 | 1.44 | 2.0736 | 1.559098 |
| 0.16 | 1.33 | -1.17 | 1.3689 | 1.029248 |
| 1.1 | 1.33 | -0.23 | 0.0529 | 0.039774 |
| 1.02 | 1.33 | -0.31 | 0.0961 | 0.072256 |
| 2.13 | 1.33 | 0.8 | 0.64 | 0.481203 |
| 0.19 | 1.33 | -1.14 | 1.2996 | 0.977143 |
| 1.21 | 1.33 | -0.12 | 0.0144 | 0.010827 |
| 1.13 | 1.33 | -0.2 | 0.04 | 0.030075 |
| 2.93 | 1.33 | 1.6 | 2.56 | 1.924812 |
| 2.14 | 1.33 | 0.81 | 0.6561 | 0.493308 |
| 0.34 | 1.33 | -0.99 | 0.9801 | 0.736917 |
| 0.44 | 1.33 | -0.89 | 0.7921 | 0.595564 |

