Jesse buys his coworkers lunch from the local steakhouse. The food cost $105.79 and the sales tax rate is 9%. Jesse wants to leave a 20% tip based on the pretax amount. How much will the total be including tax and tip.
First find the tip amount by multiplying the pre-tax amount by 20%: $105.79 * .2 = $<<105.79*.2=21.16>>21.16
Then find the tax amount by multiplying the pre-tip amount by 9%: $105.79 * .09 = $<<105.79*.09=9.52>>9.52
Then add the cost of the food, the tax, and the tip to find the total cost: $9.52 + $21.16 + $105.79 = $<<9.52+21.16+105.79=136.47>>136.47. Answer: \boxed{136.47}.