A car dealer who sells only late-model luxury cars recently hired a new salesperson and believes that this salesperson is selling at lower markups. He knows that the long-run average markup in his lot is $5,300. He takes a random sample of 25 of the new salesperson's sales and finds an average markup of $4,700 and a standard deviation of $840. Assume the markups are normally distributed. What is the value of an appropriate test statistic for the car dealer to use to test his claim?

t₂₄ = 0.75

z = 3.57

t₂₄ = 3.57

z = 0.75