Multiple choice

The mean of 10 observations is 17. One more observation is included and the new mean becomes 16. The 11th observation is

  1. 16

  2. 8

  3. 6

  4. 12

  5. Na

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The sum of the initial 10 observations is 10 * 17 = 170. When the 11th observation is included, the sum of all 11 observations becomes 11 * 16 = 176. The value of the 11th observation is the difference between these two sums, which is 176 - 170 = 6.

AI explanation

The total sum of the first 10 observations is 10 times 17, which equals 170. The new total sum for 11 observations with a mean of 16 is 11 times 16, which equals 176. The difference between the new total and the old total reveals the 11th observation; 176 minus 170 equals 6.