Question

Consider the following data:

x	−7	−6	−5	−4	−3
P(X=x)	0.2	0.1	0.2	0.2	0.3

Copy Data

Step 1 of 5:

Find the expected value E(X). Round your answer to one decimal place.

Step 2 of 5:

Find the variance. Round your answer to one decimal place.

Step 3 of 5:

Find the standard deviation. Round your answer to one decimal place.

Step 4 of 5:

Find the value of P(X>−5). Round your answer to one decimal place.

Step 5 of 5:

Find the value of P(X≥−3). Round your answer to one decimal place.

Answer 1

Solution :

x	P(x)	x * P(x)	x2 * P(x)
-7	0.2	-1.4	9.8
-6	0.1	-0.6	3.6
-5	0.2	-1	5
-4	0.2	-0.8	3.2
-3	0.3	-0.9	2.7
Sum	1	-4.7	24.3

1)

Mean = = X * P(X) = -4.7

2)

Variance = X ² * P(X) - ² = 24.3 - (-4.7)² = 2.2

3)

standard deviation = 1.5

4)

P(X>−5) = 0.2 + 0.3 = 0.5

5)

P(X≥−3) = 0.3