(R) An auto repair shop bills customers at a rate of $35 per hour for labor. Costs for parts and supplies are subject to a 7% sales tax. Given the variables labor_hours and parts_cost, calculate the total amount due for labor, parts, and the total bill. Store your results in the variables labor_cost, total_parts, and total_amt.

Here is an example console session: > labor_hours <- 9 > parts_cost <- 205 > source(...) > labor_cost [1] 315 > total_parts [1] 219.35 > total_amt [1] 534.35