Answer: 10
Step-by-step explanation:
To solve this, we have to first calculate the mean of the temperature. This will be:
= (90 + 60)/2
= 150/2
= 75°
Since the mean that we got is above 65°, we would then subtract it from 75° in order to get the number of cooling degree days. This will be:
= 75 - 65
= 10