Math Problem Statement

This is a short answer question with two parts. Type your answer in the space below​ (2 to 3​ sentences). ​ NOTE: Your answers will be graded​ manually, and the final grade will be entered into the gradebook. Suppose a simple random sample of size nequals64 is obtained from a population that is skewed right with mu equals 76 and sigma equals 24. ​(a) Describe the sampling distribution of x overbar. Be sure to describe the​ shape, center​ (mean of the sampling​ distribution), and spread​ (standard deviation of the sampling​ distribution). ​(b) How does the sampling distribution of x overbar compare to the population​ distribution?

Solution

Answer:

(a) The sampling distribution of x\overline{x} is approximately normal due to the Central Limit Theorem, since the sample size (n=64n = 64) is sufficiently large (n30n \geq 30). The center (mean of the sampling distribution) is μx=μ=76\mu_{\overline{x}} = \mu = 76, and the spread (standard deviation of the sampling distribution) is σx=σn=2464=3\sigma_{\overline{x}} = \frac{\sigma}{\sqrt{n}} = \frac{24}{\sqrt{64}} = 3.

(b) The sampling distribution of x\overline{x} is more symmetric and bell-shaped compared to the population distribution, which is skewed right. This occurs because the sampling distribution averages out the variability in the population.


Would you like further clarification or additional examples? Here are 5 related questions to expand your understanding:

  1. How does the Central Limit Theorem apply when the sample size is small?
  2. Why does increasing the sample size decrease the standard deviation of the sampling distribution?
  3. What happens to the shape of the sampling distribution if the population distribution is already normal?
  4. How do the mean and standard deviation of the sampling distribution change if nn increases to 100?
  5. How does the skewness of the population affect the sampling distribution for small samples?

Tip: Always verify that the sample size is sufficiently large when assuming the sampling distribution is normal, especially if the population distribution is skewed.

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Math Problem Analysis

Mathematical Concepts

Sampling Distribution
Central Limit Theorem
Normal Distribution

Formulas

Standard Deviation of Sampling Distribution: σ_x̄ = σ / √n
Mean of Sampling Distribution: μ_x̄ = μ

Theorems

Central Limit Theorem

Suitable Grade Level

Grades 11-12, College Introductory Statistics