The mean and the range of the set of numbers 1.20, 1.00, 0.90, 1.40, 0.80, 1.20, and 1.10 are m and r, respectively. Find m + r
A
1.11
B
1.65
C
1.85
D
2.45
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
Given:1.20, 1.00, 0.90, 1.40, 0.80, 1.20, 1.10
Sum of the numbers = 1.20 + 1.00 + 0.90 + 1.40 + 0.80 + 1.20 + 1.10
= 7.60
Number of terms = 7
Mean, m = 7.60 \div 7 = 1.0857 (to 4 d.p.)
Highest value = 1.40
Lowest value = 0.80
Range, r = 1.40 − 0.80 = 0.60
m + r = 1.0857 + 0.60 = 1.6857 closest to 1.65.
Source: Myschool Past Questions Archive (Record #33068)