Need help with an actuarial question please

An actuary produces a new standard mortality table for a country using a Poisson model to obtain estimates for the force of mortality and then graduates these model outputs by reference to a parametric formula based on Gompertz Law to produce the final table.

(a) What are the advantages and disadvantages of this method of graduation in these circumstances?

(b) The quality of the graduation is examined using a series of statistical tests with each test completed seprately for ages 0-18, 19-45, 46-65 and 66-110. The table below shows for each test whether the relevant null hypothesis was accepted or rejected at the 95% significance level.

Test	Age 0-18	Age 19-44	Age46-65	Age66-110
Chi squared	Accept	Accept	Reject	Accept
Standard deviation	Reject	Accept	Accept	Accept
Signs	Accept	Accept	Reject	Reject
Grouping of Signs	Accept	Accept	Accept	Reject

What does this set of test results tell you about the graduation?

(c) What adjustments would you recommend to the method of graduation in light of your answer to (b) above?

Thank you