Math Problem Statement

Three randomly selected children are surveyed. The ages of the children are 2 ​, 3 ​, and 10 . Assume that samples of size nequals 2 are randomly selected with replacement from the population of 2 ​, 3 ​, and 10 . Listed below are the nine different samples. Complete parts​ (a) through​ (d). 2 ​,2    2 ​,3    2 ​,10    3 ​,2    3 ​,3    3 ​,10    10 ​,2    10 ​,3    10 ​,10

Question content area bottom Part 1 a. For the​ population, find the proportion of even

numbers. The proportion is enter your response here . ​(Round to three decimal places as​ needed.) Part 2 b. Find the proportion of even

numbers of each of the nine​ samples, then summarize the sampling distribution of the sample proportion of even

numbers in the format of a table representing the probability distribution of the distinct proportion values. Sample Proportion

Probability ▼

0.2 0.1 0

enter your response here ▼

0.25 0.75 0.5

enter your response here ▼

1 0.8 0.9

enter your response here ​(Type integers or simplified​ fractions.) Part 3 c. Find the mean of the sampling distribution of the sample proportion of even

numbers. The mean is enter your response here . ​(Round to three decimal places as​ needed.) Part 4 d. Based on the preceding​ results, is the sample proportion an unbiased estimator of the population ​ proportion? Why or why​ not? A. The sample proportions target the proportion of even

numbers in the​ population, so sample proportions make good estimators of the population proportion. B. The sample proportions do not target the proportion of even

numbers in the​ population, so sample proportions do not make good estimators of the population proportion. C. The sample proportions target the proportion of even

numbers in the​ population, so sample proportions do not make good estimators of the population proportion. D. The sample proportions do not target the proportion of even

numbers in the​ population, so sample proportions make good estimators of the population proportion.

Solution

To solve the problem, let’s go through each part step by step.

Part 1: Proportion of Even Numbers in the Population

The ages of the children are 2, 3, and 10.

  • Even numbers: 2 and 10
  • Total numbers: 2, 3, and 10

The even numbers in the population are 2 and 10, so there are 2 even numbers out of 3 total.

Proportion of even numbers=Number of even agesTotal ages=230.667\text{Proportion of even numbers} = \frac{\text{Number of even ages}}{\text{Total ages}} = \frac{2}{3} \approx 0.667

Rounded to three decimal places:
The proportion is 0.667.

Part 2: Proportion of Even Numbers in Each Sample

Now, let's determine the proportion of even numbers for each of the nine samples:

  1. (2, 2): 2 even → Proportion = 1.0
  2. (2, 3): 1 even → Proportion = 0.5
  3. (2, 10): 2 even → Proportion = 1.0
  4. (3, 2): 1 even → Proportion = 0.5
  5. (3, 3): 0 even → Proportion = 0.0
  6. (3, 10): 1 even → Proportion = 0.5
  7. (10, 2): 2 even → Proportion = 1.0
  8. (10, 3): 1 even → Proportion = 0.5
  9. (10, 10): 2 even → Proportion = 1.0

Summary of the sampling distribution:

  • Proportions and their frequencies:
    • 0.0: 1 occurrence (from sample 5)
    • 0.5: 4 occurrences (from samples 2, 4, 6, 8)
    • 1.0: 4 occurrences (from samples 1, 3, 7, 9)

Probability Distribution:

Sample ProportionProbability
0.019\frac{1}{9} ≈ 0.111
0.549\frac{4}{9} ≈ 0.444
1.049\frac{4}{9} ≈ 0.444

Part 3: Mean of the Sampling Distribution

To find the mean of the sampling distribution, calculate the weighted average:

Mean=(0.019)+(0.549)+(1.049)\text{Mean} = (0.0 \cdot \frac{1}{9}) + (0.5 \cdot \frac{4}{9}) + (1.0 \cdot \frac{4}{9}) =0+29+49=69=230.667= 0 + \frac{2}{9} + \frac{4}{9} = \frac{6}{9} = \frac{2}{3} \approx 0.667

Rounded to three decimal places:
The mean is 0.667.

Part 4: Unbiased Estimator

To determine if the sample proportion is an unbiased estimator of the population proportion, we compare the mean of the sampling distribution (0.667) with the population proportion (also 0.667).

Thus, the answer is: A. The sample proportions target the proportion of even numbers in the population, so sample proportions make good estimators of the population proportion.

Summary

  1. The proportion of even numbers in the population is 0.667.
  2. The probability distribution of sample proportions is as follows:
    • 0.0: ≈ 0.111
    • 0.5: ≈ 0.444
    • 1.0: ≈ 0.444
  3. The mean of the sampling distribution is 0.667.
  4. The sample proportions are unbiased estimators of the population proportion.

If you have any questions or need further details, feel free to ask! Here are some related questions to consider:

  1. How do you calculate the variance of the sampling distribution?
  2. What would happen to the proportions if we included another age?
  3. How does sampling without replacement affect the results?
  4. What is the significance of using a sample size of 2?
  5. How could this method be applied in real-world scenarios?

Tip: Understanding sampling distributions is crucial for inferential statistics, as it helps in estimating population parameters based on sample statistics.

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Math Problem Analysis

Mathematical Concepts

Statistics
Sampling Distribution
Probability
Proportion

Formulas

Proportion of even numbers = (Number of even ages) / (Total ages)
Probability of sample proportion = (Frequency of occurrence) / (Total samples)
Mean of sampling distribution = Sum of (sample proportion * probability) over all samples

Theorems

Law of Large Numbers (for understanding unbiased estimators)

Suitable Grade Level

Grades 11-12