The results of 12 days are
1 1/2 quarts, 2 1/4 quarts, 2 quarts, 1 1/2 quarts, 1 3/4 quarts, 1 1/2 quarts, 1 1/4 quarts, 2 quarts, 2 1/4 quarts, 1 1/2 quarts, 2 quarts, and 1 1/2 quarts
This can also be written as
3/2 quarts, 9/4 quarts, 2 quarts, 3/2 quarts, 7/4 quarts, 3/2 quarts, 5/4 quarts, 2 quarts, 9/4 quarts, 3/2 quarts, 2 quarts, 3/2 quarts
Making denominator equal to 4 in all the results
6/4 quarts, 9/4 quarts, 8/4 quarts, 6/4 quarts, 7/4 quarts, 6/4 quarts, 5/4 quarts, 8/4 quarts, 9/4 quarts, 6/4 quarts, 8/4 quarts, 6/4 quarts
Given that average = 1 3/4 quarts = 7/4 quarts
On how many days did Keisha drink at least the average amount of water??
Now simply we can compare the results with the average value and count
Number of days = 6 days ( all in bold)
Now On day 13, Keisha drinks 1 quart of water. means 4/4 quarts of water
new average = (12 x 7/4 + 4/4)/13 = 22/13 = 1 9/13
New average = 1 9/13 quarts