Given a data set of five numbers: 10, 13, 15, 8, 12. What is the minimum average value that can be obtained by removing exactly one number from the set?

Step 1 ：First, calculate the total sum of the given data set: \(10 + 13 + 15 + 8 + 12 = 58\)

Step 2 ：Next, calculate the average of the set with each number removed one at a time:

Step 3 ：For removing 10: \(\frac{58 - 10}{4} = 12\)

Step 4 ：For removing 13: \(\frac{58 - 13}{4} = 11.25\)

Step 5 ：For removing 15: \(\frac{58 - 15}{4} = 10.75\)

Step 6 ：For removing 8: \(\frac{58 - 8}{4} = 12.5\)

Step 7 ：For removing 12: \(\frac{58 - 12}{4} = 11.5\)

Step 8 ：Therefore, the minimum average value is obtained by removing the number 15