I need help on how to do a vlookup formula.. The question is to add a column named Water Bill to the table, and then enter a formula to calculate the water bill based on the following rules: The billing rate varies based on the type of customer (Cust Type column). The billing rate is $3, $2, or $1.50 per thousand gallons billed, depending on the customer type (see the lookup table in cells B2:C5 of the Billing Rate worksheet). For example, a commercial customer using 75,000 gallons has a water bill of $225 (75 x $3), whereas a government customer using 100,000 gallons pays $150 (100x $1.50). A commercial customer using 15,000 gallons has a water bill of $0n (see Gal Used rule in question 3).