Answer:
0.525 = 52.5%
Explanation:
Moment generating function ( Mx(t) ) = ( 4 / 4-t)^3
Reimbursement by Insurer = 70%
Determine the expected reimbursement by insurer for policyholder
d/dx (Mx(t) ) = d/dt ( 4 / 4-t)^3 = d/dt (1 - t/4 )^-3
= 3/4 ( 1 - t/4 )^-4 = 3/4
as t → 0
Given that the insurer reimburses 70% = 0.7
expected reimbursement = 0.7 * 3/4 = 0.7 * 0.75 = 0.525