Q1) Shaver Manufacturing, Inc., provides dental insurance to its employees. A current study by human resource director illustrates annual cost per employee per year followed normal probability distribution, with mean of $1,280 and a standard deviation of $420 per year.

a) Determine fraction of employees cost more than $1,500 per year for dental expenses?

b) Compute fraction of the employees cost between $1,500 and $2,000 per year?

c) Evaluate percent that didn't have any dental expense.

d) Determine the cost for 10 percent of employees who incurred highest dental expense?