Math Problem Statement

Suppose x has a distribution with μ=84 and σ=13 . Random samples of size 82 are drawn. Calculate the following probability. Round your answer to 4 decimal places.

Solution

To solve this, we’ll calculate the probability related to the sample mean distribution, Xˉ\bar{X}, for samples of size n=82n = 82 drawn from a population where μ=84\mu = 84 and σ=13\sigma = 13.

Since the sample size n=82n = 82 is large enough (greater than 30), we can apply the Central Limit Theorem, which tells us that the distribution of the sample mean, Xˉ\bar{X}, will be approximately normal with:

  1. Mean: μXˉ=μ=84\mu_{\bar{X}} = \mu = 84
  2. Standard deviation (standard error): σXˉ=σn=1382\sigma_{\bar{X}} = \frac{\sigma}{\sqrt{n}} = \frac{13}{\sqrt{82}}

Now let’s calculate σXˉ\sigma_{\bar{X}}:

σXˉ=13821.4373\sigma_{\bar{X}} = \frac{13}{\sqrt{82}} \approx 1.4373

With this information, the sample mean distribution Xˉ\bar{X} is approximately normal with μXˉ=84\mu_{\bar{X}} = 84 and σXˉ1.4373\sigma_{\bar{X}} \approx 1.4373.

Could you specify the probability you would like calculated (e.g., P(Xˉ<a)P(\bar{X} < a), P(Xˉ>b)P(\bar{X} > b), or P(a<Xˉ<b)P(a < \bar{X} < b))?

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Statistics
Probability
Central Limit Theorem
Normal Distribution

Formulas

Standard error formula: σ/√n
Probability calculation for normal distribution

Theorems

Central Limit Theorem

Suitable Grade Level

Undergraduate Level (Introductory Statistics)