Math Problem Statement
A simple random sample of size n=40 is obtained from a population with a mean of 20 and a standard deviation of 5. Is the sampling distribution approximately normal? Why?
Yes, the sampling distribution is approximately normal because the sample size is greater than 30.
Yes, the sampling distribution is approximately normal because the population is normally distributed.
No, the sampling distribution is not approximately normal because the population is not normally distributed.
No, the sampling distribution is not approximately normal because the population mean is less than 30.
Solution
The correct answer is:
"Yes, the sampling distribution is approximately normal because the sample size is greater than 30."
Explanation:
According to the Central Limit Theorem (CLT), if the sample size is sufficiently large (typically ), the sampling distribution of the sample mean will be approximately normal, regardless of the population's distribution. In this case, since the sample size , which is greater than 30, the sampling distribution can be considered approximately normal.
Even if the population itself is not normally distributed, the CLT ensures that the sample mean's distribution approaches normality as the sample size increases.
- The second option (because the population is normally distributed) would also be correct if it were stated explicitly that the population is normal, but it isn’t given.
- The other two options are incorrect because they misunderstand the requirements of the Central Limit Theorem and the conditions for normality.
Would you like more details or have any other questions?
Related Questions:
- What is the Central Limit Theorem, and why is it important in statistics?
- How does the sample size affect the shape of the sampling distribution?
- What happens to the sampling distribution if the sample size is less than 30 and the population is not normal?
- How do we estimate the standard error of the mean in a sample?
- What is the impact of increasing the sample size on the sampling distribution?
Tip:
Always check whether the sample size meets the criteria of the Central Limit Theorem when determining if a sampling distribution is approximately normal.
Ask a new question for Free
By Image
Drop file here or Click Here to upload
Math Problem Analysis
Mathematical Concepts
Central Limit Theorem
Sampling Distribution
Normal Distribution
Formulas
Standard Error = Population Standard Deviation / sqrt(Sample Size)
Z-scores
Theorems
Central Limit Theorem
Suitable Grade Level
University Level (Introductory Statistics)
Related Recommendation
Central Limit Theorem and Sampling Distribution of the Mean
Sample Size for Normal Approximation Based on Central Limit Theorem
When Will the Sampling Distribution of the Mean be Normally Distributed?
Understanding the Central Limit Theorem in Sampling Distributions
Understanding the Central Limit Theorem: Key Concepts and Applications