According to the Internal Revenue Service, the average income tax refund for the 2018 tax year was $2,780. Assume the refund per person follows the normal probability distribution with a standard deviation of $950.

a. What is the probability that a randomly selected tax return refund from the 2018 tax year will be

1. More than $2,000?

2. Between $1,600 and $2,500?

3. Between $3,200 and $4,000?

b. Confirm the answers to part a using Excel.

c. What refund amount represents the 35th percentile of tax returns?