Math Problem Statement

Five males with an​ X-linked genetic disorder have one child each. The random variable x is the number of children among the five who inherit the​ X-linked genetic disorder. Determine whether a probability distribution is given. If a probability distribution is​ given, find its mean and standard deviation. If a probability distribution is not​ given, identify the requirements that are not satisfied. x ​P(x)

0 0.034 1 0.156 2 0.310 3 0.310 4 0.156 5 0.034 Question content area bottom Part 1 Does the table show a probability​ distribution? Select all that apply. A. ​Yes, the table shows a probability distribution. B. ​No, the sum of all the probabilities is not equal to 1. C. ​No, not every probability is between 0 and 1 inclusive. D. ​No, the random variable x is categorical instead of numerical. E. ​No, the random variable​ x's number values are not associated with probabilities.

Solution

To determine whether the given table represents a probability distribution, we need to verify two key requirements:

  1. The sum of all probabilities must equal 1: For a set of probabilities to define a distribution, the total probability of all possible outcomes must add up to 1.
  2. Each individual probability must be between 0 and 1 inclusive: Probabilities represent chances of events, so each probability must fall within this range.

Let's evaluate the given table with these criteria in mind:

xxP(x)P(x)
00.034
10.156
20.310
30.310
40.156
50.034

Step 1: Check if the sum of probabilities equals 1

We sum the probabilities: 0.034+0.156+0.310+0.310+0.156+0.034=1.0000.034 + 0.156 + 0.310 + 0.310 + 0.156 + 0.034 = 1.000 Since the sum is 1, the first condition is satisfied.

Step 2: Check if all probabilities are between 0 and 1 inclusive

We observe that all probabilities (P(x)P(x)) are within the range 0P(x)10 \leq P(x) \leq 1. This condition is also satisfied.

Conclusion:

Since both conditions are satisfied, the table does represent a valid probability distribution.

Answer:

  • The correct choice is A: "Yes, the table shows a probability distribution."

Part 2: Finding the Mean and Standard Deviation

The formulas for the mean μ\mu and standard deviation σ\sigma of a probability distribution are as follows:

  1. Mean (Expected Value) μ\mu: μ=[xP(x)]\mu = \sum [x \cdot P(x)]
  2. Variance σ2\sigma^2: σ2=[(xμ)2P(x)]\sigma^2 = \sum [(x - \mu)^2 \cdot P(x)]
  3. Standard Deviation σ\sigma: σ=σ2\sigma = \sqrt{\sigma^2}

Let's calculate the mean μ\mu:

μ=(00.034)+(10.156)+(20.310)+(30.310)+(40.156)+(50.034)\mu = (0 \cdot 0.034) + (1 \cdot 0.156) + (2 \cdot 0.310) + (3 \cdot 0.310) + (4 \cdot 0.156) + (5 \cdot 0.034) μ=0+0.156+0.620+0.930+0.624+0.170=2.5\mu = 0 + 0.156 + 0.620 + 0.930 + 0.624 + 0.170 = 2.5

So, the mean is μ=2.5\mu = 2.5.

Next, we'll calculate the variance σ2\sigma^2: σ2=(02.5)20.034+(12.5)20.156+(22.5)20.310+(32.5)20.310+(42.5)20.156+(52.5)20.034\sigma^2 = (0 - 2.5)^2 \cdot 0.034 + (1 - 2.5)^2 \cdot 0.156 + (2 - 2.5)^2 \cdot 0.310 + (3 - 2.5)^2 \cdot 0.310 + (4 - 2.5)^2 \cdot 0.156 + (5 - 2.5)^2 \cdot 0.034 σ2=(6.250.034)+(2.250.156)+(0.250.310)+(0.250.310)+(2.250.156)+(6.250.034)\sigma^2 = (6.25 \cdot 0.034) + (2.25 \cdot 0.156) + (0.25 \cdot 0.310) + (0.25 \cdot 0.310) + (2.25 \cdot 0.156) + (6.25 \cdot 0.034) σ2=0.2125+0.351+0.0775+0.0775+0.351+0.2125=1.282\sigma^2 = 0.2125 + 0.351 + 0.0775 + 0.0775 + 0.351 + 0.2125 = 1.282

Thus, the variance is σ2=1.282\sigma^2 = 1.282, and the standard deviation is: σ=1.2821.132\sigma = \sqrt{1.282} \approx 1.132

Final Answer:

  • The mean is μ=2.5\mu = 2.5.
  • The standard deviation is σ1.132\sigma \approx 1.132.

Would you like further details or have any questions?

Here are 5 related questions you might explore:

  1. How does the mean change if the probability distribution shifts?
  2. Can we calculate the mode for this distribution?
  3. What is the interpretation of standard deviation in a probability distribution?
  4. How would a change in one probability affect the overall distribution?
  5. How does variance help in understanding the spread of a distribution?

Tip: The mean of a probability distribution is often called the "expected value," representing the average outcome over many trials.

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Math Problem Analysis

Mathematical Concepts

Probability Distribution
Expected Value
Variance
Standard Deviation

Formulas

Sum of probabilities must equal 1
0 ≤ P(x) ≤ 1 for all x
Mean (Expected Value): μ = Σ[x * P(x)]
Variance: σ² = Σ[(x - μ)² * P(x)]
Standard Deviation: σ = √σ²

Theorems

Rules of Probability Distribution
Calculation of Mean (Expected Value)
Calculation of Variance and Standard Deviation

Suitable Grade Level

Grades 11-12