Problem: Last summer, two statisticians Duane and Maria played a round of 9 holes of golf each week. After finishing their seventh and final round of golf together Duane and Maria compared their individual scorecards (see below) and calculated their own average and standard deviation.

Duane: {40, 41, 42, 42, 38, 39, 41}

(Average = 40.43, Std. Deviation = 1.51)

Maria: {39, 43, 43, 40, 40, 39, 38}

(Average = 40.28, Std. Deviation = 1.98)

Of the two (Duane and Maria), who was the most consistent golfer last summer? In other words, who's golf scores had the least amount of variation. Please show steps how you get an answer and please be clear in your explanation.