In which of the following scenarios would the distribution of the sample mean x-bar be normally distributed? Check all that apply. We take repeated random samples of size 10 from a population of unknown shape. We take repeated random samples of size 15 from a population that is normally distributed. We take repeated random samples of size 50 from a population of unknown shape. We take repeated random samples of size 25 from a population that of unknown shape.
Question
In which of the following scenarios would the distribution of the sample mean x-bar be normally distributed? Check all that apply. We take repeated random samples of size 10 from a population of unknown shape. We take repeated random samples of size 15 from a population that is normally distributed. We take repeated random samples of size 50 from a population of unknown shape. We take repeated random samples of size 25 from a population that of unknown shape.
Solution
The Central Limit Theorem (CLT) states that the distribution of sample means approximates a normal distribution as the sample size gets larger — regardless of the shape of the population distribution. This rule holds true when the sample size is greater than or equal to 30.
Given this, the scenarios in which the distribution of the sample mean x-bar would be normally distributed are:
- We take repeated random samples of size 50 from a population of unknown shape.
- We take repeated random samples of size 15 from a population that is normally distributed.
In the first scenario, even though the population shape is unknown, the sample size is large enough (n>=30) for the CLT to hold. In the second scenario, the population is already normally distributed, so the sample mean would also be normally distributed, regardless of sample size.
The other two scenarios do not meet the conditions for the CLT because the sample sizes are less than 30 and the population distribution is unknown.
Similar Questions
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