How to find the angle listed below

Cassie is traveling 675 miles today to visit her brother and his family. so far, she has stopped for gas three times. at the first stop, she put in 7.1 gallons of gas and paid $23.79. at her second stop, she put in 5.8 gallons of gas and paid $19.08. and, at the third stop, 6.6 gallons and paid $20.39. at which stop did casey pay the most for gas?

Average acceleration: i have no idea how to do this.

On the first of each month sasha runs a 5k race she keeps track of her times to track her progress her time in minutes is recorded in the table