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A national study found that \(44 \%\) of college students engage in binge drinking \((5\) drinks at a sitting for men, 4 for women). Use the \(68-95-99.7\) Rule to describe the sampling distribution model for the proportion of students in a randomly selected group of 200 college students who engage in binge drinking. Do you think the appropriate conditions are met?

Short Answer

Expert verified
Yes, the conditions are met, and the sampling distribution can be modeled with a normal distribution: \(N(0.44, 0.0349)\).

Step by step solution

01

Understand the Problem

This problem involves using the 68-95-99.7 Rule (also known as the Empirical Rule) to describe the sampling distribution of proportions. We are given that 44% of college students engage in binge drinking, and we need to check if we can model the sampling distribution with a normal approximation for a sample of 200 students.
02

Check Sample Size Condition

To apply the normal approximation for the sampling distribution of a sample proportion, the conditions \(np \geq 10\) and \(n(1-p) \geq 10\) need to be met, where \(n\) is the sample size and \(p\) is the proportion. Here, \(n = 200\) and \(p = 0.44\).
03

Calculate np and n(1-p)

Calculate \(np\) and \(n(1-p)\):- \(np = 200 \times 0.44 = 88\)- \(n(1-p) = 200 \times 0.56 = 112\).Both values are greater than 10.
04

Use the 68-95-99.7 Rule

Once the conditions are met, use the 68-95-99.7 Rule to describe the distribution. The standard error (SE) for the sample proportion \(\hat{p}\) is \(SE = \sqrt{\frac{p(1-p)}{n}}\). Calculate SE and use it to define the normal distribution.
05

Calculate the Standard Error

The standard error is given by \(SE = \sqrt{\frac{0.44 \times 0.56}{200}} \approx 0.0349\). The sampling distribution of \(\hat{p}\) under a normal approximation is \(N(0.44, 0.0349)\).
06

Interpret the Rule

According to the 68-95-99.7 Rule:- 68% of sample proportions will fall within \(0.44 \pm 0.0349\) (or within \(0.4051\) to \(0.4749\)).- 95% will fall within \(0.44 \pm 2\times0.0349\) (or within \(0.3702\) to \(0.5098\)).- 99.7% will fall within \(0.44 \pm 3\times0.0349\) (or within \(0.3353\) to \(0.5447\)).

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

68-95-99.7 Rule
The 68-95-99.7 Rule, also known as the Empirical Rule, is a key concept in statistics. It helps us understand how data is spread out in a normal distribution. This rule suggests that:
  • 68% of the data points fall within one standard deviation (\(\sigma\)) of the mean.
  • 95% fall within two standard deviations.
  • 99.7% fall within three standard deviations.
This rule is particularly useful when dealing with normal distributions. These distributions tend to have the classic bell-shaped curve. If you have a random variable that is normally distributed, you can apply this rule to estimate the likelihood of the data falling within certain ranges.
In our context, the 68-95-99.7 Rule helps us predict how the sample proportions of college students who engage in binge drinking will spread around the mean when measuring different groups. Understanding this rule is foundational to appreciating how well data will conform to typical patterns in large populations.
Normal Approximation
In statistics, normal approximation is used when we want to apply the characteristics of a normal distribution to approximate other distributions. In particular, it's useful for calculating probabilities about sample proportions when the sample size is sufficiently large.
The normal approximation is applicable to binomial distributions under certain conditions, especially when the sample size (\(n\)) is large, and the probability of success (\(p\)) is not too close to 0 or 1. With large enough samples, the distribution of the sample proportion (\(\hat{p}\)) becomes roughly normal.
In our example, we're interested in the proportion of college students engaging in binge drinking. With a sample size of 200 and a proportion of 44% (or 0.44), our binomial distribution qualifies for a normal approximation since both \(np\) and \(n(1-p)\) are greater than 10. This allows us to use the properties of normal distributions to make predictions about the proportion of students who might binge drink in different samples of 200 students.
Standard Error
The standard error (SE) is a measure of the statistical accuracy of an estimate. It signifies how much a sample proportion is expected to vary from the actual population proportion just by chance.
The formula for calculating the standard error of a sample proportion is:\[SE = \sqrt{\frac{p(1-p)}{n}}\]where \(p\) is the population proportion, and \(n\) is the sample size. This formula gives us an understanding of the spread of sample proportions around the mean proportion.
In our specific problem, the standard error can be calculated as follows: given \(p = 0.44\) and \(n = 200\), the standard error is approximately \(0.0349\). This indicates not only the reliability of our sampling but also helps indicate how far off the sample proportion might be from the actual population proportion. Understanding standard error is crucial for interpreting results, particularly when considering the variability and confidence intervals applied to sampled data.
College Students Binge Drinking
Binge drinking among college students is a prevalent issue and is defined in the study by consuming 5 drinks in one sitting for men and 4 for women. According to the exercise, 44% of college students reportedly engage in this behavior.
Considering a sample of 200 college students, our task is to assess how this proportion can reflect upon larger groups of students. By using statistical methods like the 68-95-99.7 Rule along with normal approximation and calculating standard error, we can attain a clearer picture of the binge drinking phenomenon in colleges.
These methods allow educators, policymakers, and students to better understand the prevalence and potential impact of binge drinking among their peers, and to institute informed curriculums or interventions where necessary. Understanding the statistical representation of such behaviors in college settings provides a foundation for tackling them constructively and can be a catalyst for positive change in these communities.

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Most popular questions from this chapter

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