Answer:
Sara's percentage yield of gas mileage is approximately 90.7%
Step-by-step explanation:
Percentage yield of an process is given by the ratio of the observed, experienced (calculated), or actual yield to the theoretical yield of the process and then multiplying the result by 100%
The theoretical yield of Sara's car is the mileage advertised for the car which the car has 'ideally' which is 43 miles per gallon
∴ The theoretical yield = 43 miles/gallon
The actual yield is the yield of the car Sara is able to calculate, based on how she uses the car which is 39 miles per gallon
∴ The actual yield = 39 miles/gallon
Sara's percentage yield of gas mileage for the car, % yield, therefore is given as follows;
% yield = (39 miles/gallon)/(43 miles/gallon) × 100 ≈ 90.7%
Sara's percentage yield of gas mileage, % yield ≈ 90.7%.