Answer:
3.6
Step-by-step explanation:
1. Find the Mean
(20+16+18+14+9+20+16)/7 = 16.1
2.For each number, subtract the Mean and square the result.
(20-16.1)^2=15.2
(16-16.1)^2=0
(18-16.1)^2=3.6
(14-16.1)^2=4.4
(9-16.1)^2=50.4
(20-16.1)^2=15.2
(16-16.1)^2=0
3. Find the Mean of those squared differences.
(15.2+0+3.6+4.4+50.4+15.2+0)/7=12.7
4.Take the square root of that and this is what you want.
square root of 12.7 = 3.6
