Question

Hannah has a chicken coop with 6 hens. Let X be the total number of eggs the hens lay on a randomly chosen day. The distribution for X is given in the table.

A 2-column table with 7 rows. Column 1 is labeled number of eggs with entries 0, 1, 2, 3, 4, 5, 6. Column 2 is labeled probability with entries 0.02, 0.03, 0.07, 0.12, 0.30, 0.28, 0.18.

What is the standard deviation of the distribution?

1.39
1.95
2.16
4.67

Answer 1

1.39

Explanation:

Creating a table:

X :___0 __ 1 __ 2 ___ 3 ____ 4 ___ 5 ___ 6

P(x):0.02_0.03_0.07, 0.12, 0.30_ 0.28_0.18.

The standard deviation = sqrt(Var(x))

Var(x) = Σx²*p(x) - E(x)²

E(x) = ΣX*p(x)

E(x) = (0*0.02) + (1*0.03) + (2*0.07) + (3*0.12) + (4*0.30) + (5*0.28) + (6*0.18) = 4.21

Var(X) :

((0^2*0.02) + (1^2*0.03) + (2^2*0.07) + (3^2*0.12) + (4^2*0.30) + (5^2*0.28) + (6^2*0.18)) - 4.21^2

19.67 - 17.7241

= 1.9459

Standard deviation = sqrt(Var(X))

Standard deviation = sqrt(1.9459)

Standard deviation = 1.3949551

= 1.39