Answer:
The probability of receiving reimbursement within 42 days of filing is 0.8849 = 88.49%
Step-by-step explanation:
Let the probability of being reimbursed in an interval of a to b days, we want
First, standardize x by doing the change
where is the mean of our original distribution and the standard deviation. So
This change transforms the original distribution in a normal distribution N(0,1) with mean 0 and standard deviation 1.
This is done in order to easily compute the area under the normal curve.
Since,
we then have
And we want the area under the normal curve between -7.2 and 1.2. This can be done either by using a table or a computer, and we find this area is 0.8849,
Hence, the probability of receiving reimbursement within 42 days of filing is 0.8849 = 88.49%