We have the data set {2,4,9,3,5,7,8,12,15,18}. Calculate the range, variance, and standard deviation, and then find the minimum among these calculated values.

Step 1 ：Step 1: Arrange the data in ascending order: {2,3,4,5,7,8,9,12,15,18}

Step 2 ：Step 2: Calculate the range, which is the difference between the maximum and minimum data values. Range = 18 - 2 = 16

Step 3 ：Step 3: Calculate the mean (average) of the data set. Mean = \(\frac{2+3+4+5+7+8+9+12+15+18}{10} = 8.3\)

Step 4 ：Step 4: Calculate the variance, which involves subtracting the mean from each data value, squaring the result, adding all these square values together, then dividing by the number of data values. Variance = \(\frac{(2-8.3)^2+(3-8.3)^2+(4-8.3)^2+(5-8.3)^2+(7-8.3)^2+(8-8.3)^2+(9-8.3)^2+(12-8.3)^2+(15-8.3)^2+(18-8.3)^2}{10} = 26.61\)

Step 5 ：Step 5: Calculate the standard deviation, which is the square root of the variance. Standard Deviation = \(\sqrt{26.61} = 5.16\)

Step 6 ：Step 6: Find the minimum among these calculated values. The minimum is 5.16.