Interpreting with confidence: analysis of sample data

Question 1

What is the standard normal distribution?

Answer 1

A normal distribution with a mean of 0 and variance of 1.

Question 2

What are z-values?

Answer 2

A standardised measure that represents the number of standard deviations a data point is away from the mean in a standard normal distribution.

Question 3

What is the difference between standard deviation calculations for a population and a sample?

Answer 3

We use n in the formula for standard deviation of a POPULATION.
And we use n-1 (instead of n) in the formula for standard deviation of a SAMPLE.

Question 4

What is the confidence interval?

Answer 4

A confidence interval is a range of values in which we estimate the population mean or proportion will lie with a specified probability (confidence level).