Homework SourseQuestion 21 The number of fatal car crashes per day in Houst
Question 21
The number of fatal car crashes per day in Houston is shown in the table below. Let X be the random variable representing the number of fatal crashes. Find P(X < 2). Hint: convert the table to a probability distribution first by dividing the \"Days\" column by the total numberof days.
| Number of Fatal Crashes | Number of Days |
| 0 | 107 |
| 1 | 163 |
| 2 | 98 |
| 3 | 38 |
| 4 | 7 |
| 5 | 3 |
Solution
Total number of days is 107+163+98+38+7+3=416
Following table shows the distribution of X:
So,
P(X<2)=P(X=0)+P(X=1)= 0.257212+0.391827=0.649039
Hence, the required probability is 0.649.
| Number of Fatal Crashes (X) | Number of Days | P(X) | P(X) |
| 0 | 107 | 107/416 | 0.257212 |
| 1 | 163 | 163/416 | 0.391827 |
| 2 | 98 | 98/416 | 0.235577 |
| 3 | 38 | 38/416 | 0.091346 |
| 4 | 7 | 7/416 | 0.016827 |
| 5 | 3 | 3/416 | 0.007212 |
| Total | 416 | 1 |
