Question

Q4 - Exam prep: Missing values

Audrey measures all 7 pencils in her pencil case and writes the first 6 lengths down.
11.8 cm, 12.9 cm, 13 cm, 13.2 cm, 14 cm, 13.5 cm
Audrey calculates the mean length of all 7 pencils to be 11.7 cm.
Find the length of the missing pencil.
cm
[2]

Answer 1

3.99 or 4

Explanation:

The sum of the six known measurements is 78.4

3.99+78.4=82.39

Divide 82.39 by seven to get the average and it equals 11.77