Question

The average (arithmetic mean) of k scores

Answer 1

Answer:

(E) (20k - 150)/(k - 10)

Step-by-step explanation:

Sum of all scores = average × number of scores = 20 × k = 20k

                   Sum of 10 scores = 15 × 10 =150

      Sum of remaining scores = 20k - 150

Number of remaining scores = k -10

Average of remaining scores = sum of remaining/no. remaining

= (20 k -150)/(k-10)