how should i find the number of cases asked in the below question?

Question

For the question, please follow the file called airplane crashes.txt while reading the text below. In each year from 1993 to 2012, the number of airplane crashes in airline companies were counted. The data was collected from 14 different airline companies. The numbers of crashes for the airline companies are indicated in 14 columns following the year column. Assume that the number of crashes per airline company per year is a random variable having a Poisson(λ) and that the number of crashes in different airline company or in different years are independent.

Give a table how many cases occur for all companies between 1993 and 2012 for each number of crashes (# of Crashes).

Hint: When you check the file you will see: # of Crashes = {0, 1, 2, 3, 4}.

Answer 1

Ashraf

I assume your file contains one row per year and 14 columns, one per company, then each cell contains 0/1/2/3/4.

To find your table you just have to count up how many zeroes, ones, twos, threes and fours you see in this table. The total frequency should be 20 x 14 = 280 as you have 20 years and 14 companies.

Mike