No, it did not increase by a third between 1966 and 1976.
Explanation:
Step 1:
First, we need to determine what the values of average miles flown per passenger in 1966 and 1976.
The average miles flown per passenger in 1966 = 711.
The average miles flown per passenger in 1976 = 831.
Step 2:
To calculate the percent increase, we divide the difference in values by the value in the past.
% increase =
.
So there was an increase of 15.56%.
Step 3:
An increase of one-third is a % increase of 33.33%. As the actual increase is only 15.56%, the given statement is false.