Question

The mean of 5 numbers is 25. If the four numbers 16, 26, 31, 32. Find the fifth number.

Answer 1

Answer:

The fifth number = 20

Step-by-step explanation:

The mean of 5 numbers is 25.

∴ The sum of those 5 numbers is 5x25 = 125

Four numbers are 16, 26, 31, and 32.

Sum of these four numbers = 16 + 26 + 31 + 32

= (20 - 4) + (30 - 4) + (30 + 1) + (30 + 2) = 20 + 3x30 - 8 + 3 = 110 - 5 = 105

∴ The fifth number = The sum of five numbers - The sum of four numbers

= 125 - 105 = 20

Answer 2

Answer:

the fifth number is 20.

Step-by-step explanation:

Let the fifth number is x

mean = Number of observations / Total number of observations

( 16 + 26 + 31 + 32 + x ) / 5 = 25

(105 + x ) / 5 = 25

105 + x = 25 × 5

105 + x = 125

x = 125 - 105

x = 20