A student was asked to find the value of x, and given the arithmetic mean is 12 of the following 12 numbers: 3, 11, 7, 9, 15, 13, 8, 19, 17, 21, 14 and x
Answer & explanation
Correct answer: option 2
Mean = \(\frac{sum \; of \; observations}{number \; of \; observations}\)
Given mean = 12
Mean = \(\frac{3 + 11 + 7 + 9 + 15 + 13 + 8 + 19 + 17 + 21 + 14 + x}{12}\) = 12
137 + x = 12 × 12
x = 7