If f(x)=0 what is x?

How many solutions does the nonlinear system of equations graphed bellow have?

The total number of dental clinics total for the last 12 months was recorded

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?