Answer:
Standard Deviation, σ: 5.2805584478028
Step-by-step explanation:
Count, N: 11
Sum, Σx: 82
Mean, μ: 7.4545454545455
Variance, σ2: 27.884297520661
Steps
σ =radical 1/N Σ(xi - μ)squared (N i=1)
σ2= (12 - 7.4545454545455)2 + ... + (19 - 7.4545454545455)2/ 11
= 306.72727272727/ 11
= 27.884297520661
σ = √27.884297520661
= 5.2805584478028
