Adding populations to aggregate data

[May Blake]

hi, I have an aggregate dataset that I would like to do simple chi square and t-test on. I imagine this is a simple task but I am stuck. I would like a three way summary looking at 2 separate tables of fatalities and non-fatalities, each looking at the mean of injuries by airline and gender. I can do this very easily with my code below. But I also have the total number of flights for each airline, airline 1, n = 553 and airline 2, n = 678. I am not sure how to incorporate these two totals into the analysis. Do I create a new variable by airline that has repeated values of these Ns? How do I incorporate the Ns into the analysis? Do I use them as weight factors? Thank you in advance.

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keep if fatality==1

bysort airline gender: sum (injuries)

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* Example generated by -dataex-. For more info, type help dataex

clear

input byte(airline injuries) double gender byte fatality

1 11 0 1

1  7 0 0

1  7 1 0

1 19 0 0

2  9 0 0

2  4 1 1

2  3 1 0

2  1 1 0

2  3 0 1

end

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