Answer:
standard deviation =3.11
Explanation:
data given is ungrouped data
standard deviation =√ [∑ (x-μ)² / n]
mean (μ)=∑x/n
=
=14.57
x-μ for data 10, 15, 12, 18, 19, 16, 12 will be
-4.57, 0.43, -2.57, 3.43, 4.43,1.43, -2.57
(x-μ)² will be 20.88, 0.1849, 6.6049, 11.7649,19.6249, 2.0449, 6.6049
∑ (x-μ)² will be = 67.7049
standard deviation = √(67.7049 / 7)
=3.11