Given:
The numbers are 40, 20, 45, 40, 35, 25, 30 and x
Formula used:
Average = Sum of all numbers/ Total numbers
Calculation:
Sum of these numbers are = 40 + 20 + 45 + 40 + 35 + 25 + 30 + x = 235 + x
The average of these numbers is = 35
We know that Average of some numbers = Total sum of these numbers / Total number of Numbers
⇒ 35 = (235 + x)/8 (∴ Substituting the values)
⇒ 35 × 8 = 235 + x
⇒ 235 + x = 280
⇒ x = 280 -235 = 45
Hence the answer is 45.