Unit 2.4 test review P1

True

0.3% (This represents the tails of the normal distribution outside of 3 standard deviations from the mean.)

6 (Mean is calculated by summing all numbers and dividing by the count.)

6.89 (Standard deviation measures the amount of variation or dispersion in a set of values.)

3870 (Use the standard normal distribution to find the proportion of the population within this age range.)

Standard deviation is a measure of the amount of variation or dispersion in a set of values.

Mean = (Sum of all values) / (Number of values)

The empirical rule states that for a normal distribution, approximately 68% of the data falls within one standard deviation of the mean, 95% within two standard deviations, and 99.7% within three standard deviations.

Data is normally distributed if it follows a bell-shaped curve, where most of the observations cluster around the central peak and probabilities for values further away from the mean taper off equally in both directions.

Variance = (Sum of squared differences from the mean) / (Number of values) or (N-1 for sample variance).