Math Problem Statement

The image contains a statistical problem involving assumptions, naming a procedure, and calculating a 1-proportion Z-interval for given data.

Solution

The image contains a statistical problem that involves evaluating assumptions, naming procedures, and calculating intervals for a proportion. Here's a step-by-step breakdown of the task:


1. Evaluate Assumptions

The assumptions to check include:

  • np^10n \hat{p} \geq 10
  • n(1p^)10n (1 - \hat{p}) \geq 10
  • N10nN \geq 10 \cdot n

From the problem:

  • n=3350n = 3350, p^=46333500.1382\hat{p} = \frac{463}{3350} \approx 0.1382
  • Calculate np^n \hat{p} and n(1p^)n (1 - \hat{p}):
    • np^=33500.1382463n \hat{p} = 3350 \cdot 0.1382 \approx 463 (passes the condition since 10\geq 10).
    • n(1p^)=3350(10.1382)33500.86182887.03n (1 - \hat{p}) = 3350 \cdot (1 - 0.1382) \approx 3350 \cdot 0.8618 \approx 2887.03 (passes the condition since 10\geq 10).

The third assumption:

  • N10nN \geq 10 \cdot n:
    • N=1,000,000N = 1,000,000, 103350=33,50010 \cdot 3350 = 33,500.
    • N33,500N \geq 33,500 (passes the condition).

2. Name the Procedure

Based on the conditions:

  • Use the 1-Proportion Z-Interval, as the conditions for the normal approximation are met.

3. Point Estimate

The point estimate p^\hat{p} is: p^=xn=46333500.1382.\hat{p} = \frac{x}{n} = \frac{463}{3350} \approx 0.1382.


4. Confidence Interval

To calculate the confidence interval: p^±zp^(1p^)n,\hat{p} \pm z \cdot \sqrt{\frac{\hat{p}(1 - \hat{p})}{n}}, where zz depends on the confidence level.

  • For a 95% confidence level, z=1.96z = 1.96.
  • Plug values: = 1.96 \cdot \sqrt{\frac{0.1382 \cdot 0.8618}{3350}} = 1.96 \cdot \sqrt{\frac{0.11903}{3350}} = 1.96 \cdot \sqrt{0.00003554} = 1.96 \cdot 0.00596 \approx 0.0117.$$
  • Confidence interval: 0.1382±0.0117    (0.1265,0.1499).0.1382 \pm 0.0117 \implies (0.1265, 0.1499).

Summary of Results

  • Point estimate: p^=46333500.1382\hat{p} = \frac{463}{3350} \approx 0.1382.
  • Confidence interval: (0.126,0.150)(0.126, 0.150).

Would you like further details or calculations?


Related Questions:

  1. What are the specific interpretations of the assumptions np^n \hat{p} and n(1p^)n (1 - \hat{p})?
  2. How is the zz-value determined for different confidence levels?
  3. What is the significance of a confidence interval in hypothesis testing?
  4. How does the sample size nn affect the width of the confidence interval?
  5. What would happen if the assumptions for the normal approximation weren’t satisfied?

Tip: Always verify your assumptions before applying statistical methods; failing to do so may lead to invalid conclusions.

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Math Problem Analysis

Mathematical Concepts

Statistical Inference
Confidence Intervals
Proportion Analysis

Formulas

n * p̂ ≥ 10
n * (1 - p̂) ≥ 10
Confidence Interval Formula: p̂ ± z * sqrt((p̂ * (1 - p̂)) / n)

Theorems

Central Limit Theorem for Proportions
Properties of the Normal Distribution

Suitable Grade Level

Undergraduate Statistics