For those who may still need it in the future, the correct answer is actually: D: 3(x^2 + 1) +2
18/12=22.50/n
he could buy 15 gallons
Total Numbers = 5
Mean (Average) = 85.2
Standard deviation = 10.70981
Variance(Standard deviation) = 114.7
Population Standard deviation = 9.57914
Variance(Population Standard deviation) = 91.76
