Math Problem Statement

A magazine provided results from a poll of 1500 adults who were asked to identify their favorite pie. Among the 1500 ​respondents, 13​% chose chocolate​ pie, and the margin of error was given as plus or minus5 percentage points. What values do ModifyingAbove p with caret​, ModifyingAbove q with caret​, ​n, E, and p​ represent? If the confidence level is 95​%, what is the value of alpha​?

Solution

In this problem, you're provided with results from a poll and are asked to determine various values related to the sample proportion and confidence level. Let's define and calculate these values step by step.

  1. ModifyingAbove p with caret ( p^\hat{p}): This represents the sample proportion of respondents who chose chocolate pie.

    • p^=13%100=0.13\hat{p} = \frac{13\%}{100} = 0.13
  2. ModifyingAbove q with caret ( q^\hat{q}): This represents the proportion of respondents who did not choose chocolate pie. It's simply the complement of p^\hat{p}, so:

    • q^=1p^=10.13=0.87\hat{q} = 1 - \hat{p} = 1 - 0.13 = 0.87
  3. n: This represents the sample size, which is given as 1500.

    • n=1500n = 1500
  4. E (Margin of Error): This is the maximum expected difference between the sample proportion and the true population proportion. It is given as ±5 percentage points.

    • E=5%E = 5\% or 0.05
  5. p (True Population Proportion): The true population proportion pp is unknown in this context. The sample proportion p^\hat{p} is an estimate of pp, but we do not know the exact value of pp.


Now, let's determine the value of alpha ( α\alpha):

  • The confidence level is given as 95%. The confidence level and alpha (α\alpha) are related as follows:
    • α=1Confidence Level\alpha = 1 - \text{Confidence Level}
    • α=10.95=0.05\alpha = 1 - 0.95 = 0.05

Therefore, the value of α\alpha is 0.05.


Summary:

  • p^=0.13\hat{p} = 0.13
  • q^=0.87\hat{q} = 0.87
  • n=1500n = 1500
  • E=0.05E = 0.05
  • α=0.05\alpha = 0.05

Do you want any further details or have questions on these calculations?

Here are five related questions to expand your understanding:

  1. How do we calculate the confidence interval based on the margin of error?
  2. How can we interpret the meaning of a 95% confidence level?
  3. What effect does increasing the sample size have on the margin of error?
  4. How is the margin of error derived using standard error and the z-score?
  5. What does the alpha value tell us about the probability of making a Type I error?

Tip: In most cases, increasing the sample size will reduce the margin of error, leading to a more precise estimate of the population parameter.

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Math Problem Analysis

Mathematical Concepts

Statistics
Confidence Intervals
Proportions
Margin of Error

Formulas

Sample Proportion: p̂ = x/n
Complement of Proportion: q̂ = 1 - p̂
Alpha: α = 1 - Confidence Level

Theorems

Central Limit Theorem

Suitable Grade Level

Grades 10-12