Correct Answer - Option 2 : 7
Given:
Data = (1, 5, 9, 2, 2, 3, x, a, 9)
Arithmetic mean = 5
Formula Used:
Arithmetic mean = Sum of terms/Number of terms
Calculations:
Number of terms = 9
Sum of terms = 1 + 5 + 9 + 2 + 2 + 3 + x + a + 9
⇒ Sum of terms = 31 + a + x
Arithmetic mean = Sum of terms/Number of terms
⇒ 5 = (31 + a + x)/9
⇒ (31 + a + x) = 5 × 9
⇒ (31 + a + x) = 45
⇒ a + x = 45 - 31 = 14
Arithmetic mean of a and x = (a + x)/2
⇒ Arithmetic mean of a and x = 14/2
⇒ Arithmetic mean of a and x = 7
∴ The arithmetic mean of a and x is 7.
