1. In the chapter, the original labor rate for inspectors was given as $35 per hour. However, because of contract renegotiation, this value is now $40. What algebraic expression could you use to determine the percent increase in labor costs? Provide the formula and resulting value.

2. The formula =ROUND(810.52,-1) results in what precise value?
3. Write a formula to round down 83.34% to the nearest percent.
4. What is the symbol for the not equal the o relational operator in Excel?