The random variable x represents the races won by a driver in one season. Use the frequency distribution to construct a probability distribution. Find the Standard Deviation.
wins 1 2 3 4 5 6 7
drivers 12 2 0 2 0 0 1

Respuesta :

The standard deviation of the distribution is 1.62

What is a probability distribution?

A probability distribution shows how individual probabilities are distributed

The table entries are given as:

wins 1 2 3 4 5 6 7

drivers 12 2 0 2 0 0 1

Calculate the total number of drivers

[tex]Total = 12 +2+0+2+0+0+1[/tex]

[tex]Total = 17[/tex]

Divide the number of drivers by the total, to determine the probability distribution

The probability distribution is as follows:

Wins           Drivers           P(x)

1                       12              0.71

2                       2               0.12

3                       0                 0

4                       2                0.12

5                       0                 0

6                       0                 0

7                        1                0.06

How to calculate the standard deviation

We start by calculating the variance using:

[tex]V(x) = E(x^2) - E(x)^2[/tex]

Where:

[tex]E(x) = \sum x \times P(x)[/tex]

So, we have:

[tex]E(x) = 1 \times 0.71 + 2 \times 0.12 + 3 \times 0 +4 \times 0.12 + 5 \times 0 + 6 \times 0 + 7 \times 0.06[/tex]

[tex]E(x) = 1.85[/tex]

[tex]E(x^2) = 1^2 \times 0.71 + 2^2 \times 0.12 + 3^2 \times 0 +4^2 \times 0.12 + 5^2 \times 0 + 6^2 \times 0 + 7^2 \times 0.06[/tex]

[tex]E(x^2) = 6.05[/tex]

The equation becomes

[tex]V(x) = E(x^2) - E(x)^2[/tex]

[tex]V(x) = 6.05 - 1.85^2[/tex]

[tex]V(x) = 2.63[/tex]

Take the square root of the variance, to calculate the standard deviation.

[tex]\sigma = \sqrt{2.63[/tex]

[tex]\sigma = 1.62[/tex]

Hence, the standard deviation is 1.62

Read more about probability distribution at:

https://brainly.com/question/15246027

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