Answer:
We need to do difference so we can have how many numbers differ between the 2 numbers
Step-by-step explanation:
For example: 5-2=? We want to know what is the difference between the number which is 3 hope I explained it the best I can!!
Answer:
7/12 of an hour or 35 minutes
Step-by-step explanation:
Answer: 0.3679
Step-by-step explanation:
The cumulative distribution function for exponential distribution is :-
, where
is the mean of the distribution.
Given : A mean length of waiting time equal
minutes
i.e. Mean number of calls answered in a minute 
Now, the proportion of callers is put on hold longer than 2.8 minutes is given by :_

Hence, the proportion of callers is put on hold longer than 2.8 minutes = 0.3679
Greater than 90° but less than 180°.