Working on a commission: A certain man works in sales and earns a base salary of $1000 per month plus 5% of his total sales for the month. a. Explain why his total monthly income I is a linear...

Working on a commission: A certain man works in sales and earns a base salary of $1000 per month plus 5% of his total sales for the month.

a. Explain why his total monthly income I is a linear function of total sales S, both measured in dollars.

b. How much does he earn if he sells $1600 in merchandise in a month?

c. Write a formula that gives total monthly income as a linear function of sales in a month.

d. What should his monthly total sales be if he wishes to earn $1350 this month?