Answer:
11.38 g
0.014142
Step-by-step explanation:
part a
Mean = Sum of all results / No. of results
Mean = (11.36 + 11.37 + 11.40 + 11.38 + 11.39) / 5
Mean = 11.38 g = E (X)
part b
Var (X) = E (X^2) - (E(X))^2
S.d = sqrt (Var (X))
Compute E (X^2):
E (X^2) = (11.36^2 + 11.37^2 + 11.40^2 + 11.38^2 + 11.39^2) / 5
E (X^2) = 129.5046
(E(X))^2 = 11.38^2 = 129.5044
Var (X) = 129.5046 - 129.5044 = 0.0002
s.d = sqrt (0.0002) = 0.014142