Lecture 7 (cis)

Question 1

what is sampling and normal distribution ??

Answer 1

when using samples, results vary from one sample to another.

sampling distribution represents how sample statistics (like mean) behave.

standard error measures variation in sample means.

Question 2

What is a large sampling distribution ?

Answer 2

A larger sample sizes reduces random variation, making the sample mean more stable and accurate.

This results in a small standard error, meaning the estimate of the population mean is more reliable.

Question 3

what is the central limit theorem (clt) ?

Answer 3

no matter how large the samples (n>=30), the sampling distribution of the mean is approximately normal, even if the original distribution is not normal.

Question 4

Introducing confidence intervals (cis)

Answer 4

A confidence interval (ci) estimates a population parameter using a sample statistic.

Instead of a single value, CI provides a range within the true mean is likely to fall.

Question 5

Formula for cis

Answer 5

Sample Statistic +/- Margin of Error

Question 6

What is margin of error ?

Answer 6

demonstrate how much a sample result might differ from the actual population value just by chance.

A smaller margin means the result is more trustworthy and close to the true population value.