Answer:
a
b
Step-by-step explanation:
From the question we are told that
The mean is
The standard deviation is
Generally 2 year is equal to 24 months
Generally the percentage of total production will the company expect to replace is mathematically represented as
Generally
Generally from the z-table
So
Converting to percentage
=>
Generally the duration that should be the guarantee period if Accrotime does not want to make refunds on more than 6% is mathematically evaluated as
=>
From the normal distribution table the z-score for 0.06 at the lower tail is
So
=>
