The owner of a car wash wants to see if the arrival rate of cars follows a Poisson distribution. In order to test the assumption of a Poisson distribution, a random sample of 150 ten-minute intervals was taken. You are given the following observed frequencies: 
Number of Cars Arriving in a 10-Minute Interval Frequency 
0 3 
1 10 
2 15 
3 23 
4 30 
5 24 
6 20 
7 13 
8 8 
9 or more 4 
150 
The calculated value for the test statistic equals:_______