The average height of a group of 16 students was 164 cm. Four students of height 153 cm, 158 cm, 166 cm, and 145 cm left the group. Nine new students of average height 167 cm joined the remaining group. What is the new average (in cm. to the nearest whole number) of the students in the group?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 167.
Original total height = 16 × 164 = 2624 cm
Total height of 4 students who left = 153 + 158 + 166 + 145 = 622 cm
New total after they left = 2624 – 622 = 2002 cm
Height of 9 new students = 9 × 167 = 1503 cm
New total = 2002 + 1503 = 3505 cm
Total students now = (16 – 4) + 9 = 21 students
New average = = 167