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In the accompanying table, the random variable x represents the number of televisions in a household in a certain country. Determine whether or not the table is a probability distribution. If it is a probability distribution, find its mean and standard deviation.

x P(x)
0 0.05
1 0.12
2 0.28
3 0.27
4 0.17
5 0.11

If the table is a probability distribution, what is its mean? Select the correct choice below and fill in any answer boxes within your choice.

A .Its mean is __.
(Round to the nearest tenth as needed.)

User Mhbdr
by
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1 Answer

4 votes

A. Its mean is 2.7 (rounded to the nearest tenth).

To determine whether the table is a probability distribution, we need to check two conditions:

The probabilities must be non-negative: P(x) ≥ 0 for all x.

The sum of all probabilities must be equal to 1: Σ P(x) = 1 over all possible values of x.

Let's check these conditions:

All probabilities in the given table are non-negative, so the first condition is satisfied.

Summing up the probabilities:

0.05 + 0.12 + 0.28 + 0.27 + 0.17 + 0.11 = 1.00

Both conditions are satisfied, so the table is a probability distribution.

Now, to find the mean (μ) of the probability distribution, you can use the formula:

μ=∑i xi ⋅ P(xi )

where xi is the value of the random variable, and P(xi ) is the probability of xi.

μ=(0⋅0.05)+(1⋅0.12)+(2⋅0.28)+(3⋅0.27)+(4⋅0.17)+(5⋅0.11)

μ=0+0.12+0.56+0.81+0.68+0.55

μ=2.72

So, the mean of the probability distribution is 2.72 (rounded to the nearest tenth).

Therefore, the correct choice is:

A. Its mean is 2.7 (rounded to the nearest tenth).

User Drbarnard
by
8.0k points
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