Math Problem Statement

Answer part 2

Find the standard deviation (σ̂p) for a sample proportion, given a population proportion (p = 0.48) and sample size (n = 150).

Solution

For Part 2 of 6, you are asked to find the standard deviation (σp^\sigma_{\hat{p}}) of the sampling distribution for the proportion of teenagers who own smartphones.

The formula for the standard deviation of the sampling distribution of a sample proportion is:

σp^=p(1p)n\sigma_{\hat{p}} = \sqrt{\frac{p(1 - p)}{n}}

Where:

  • pp is the population proportion (in this case, p=0.48p = 0.48, or 48%),
  • nn is the sample size (given as n=150n = 150).

Now, let's calculate it:

σp^=0.48(10.48)150=0.48×0.52150=0.2496150=0.0016640.0408\sigma_{\hat{p}} = \sqrt{\frac{0.48(1 - 0.48)}{150}} = \sqrt{\frac{0.48 \times 0.52}{150}} = \sqrt{\frac{0.2496}{150}} = \sqrt{0.001664} \approx 0.0408

Thus, the standard deviation σp^\sigma_{\hat{p}} is approximately 0.0408.

Would you like further explanation or details?

Here are 5 related questions you might consider:

  1. What is the significance of the standard deviation in a sampling distribution?
  2. How does increasing the sample size affect the standard deviation?
  3. How do you interpret the value of σp^\sigma_{\hat{p}}?
  4. Can the standard deviation of a sample proportion be larger than the population proportion itself?
  5. Why is it important to use a random sample when calculating statistics like this?

Tip: Always remember to check whether your sample size nn is large enough to meet the conditions for normal approximation when using proportions (i.e., np10np \geq 10 and n(1p)10n(1-p) \geq 10).

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Math Problem Analysis

Mathematical Concepts

Inferential Statistics
Sampling Distribution
Proportions

Formulas

σ̂p = √(p(1 - p) / n)

Theorems

Central Limit Theorem

Suitable Grade Level

Grades 11-12