Unit 2.4 test review P1

Front

TRUE or FALSE: There are two types of standard deviation: population and sample.

Back

True

Front

This data is normally distributed. What percent of the data is in the shaded region?

Back

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

Front

Find the mean of these numbers: 5, 11, 2, 12, 4, 2

Back

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

Front

What is the standard deviation for the data given: 5, 10, 7, 12, 0, 20, 15, 22, 8, 2?

Back

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

Front

The ages of the population of people living in Meru area in Ipoh are Normally distributed with mean 43 and standard deviation 14. How many would you expect to be aged between 22 and 57?

Back

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

Front

Define standard deviation.

Back

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

Front

What is the formula for calculating the mean?

Back

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

Front

Explain the empirical rule in statistics.

Back

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.

Front

What does it mean if data is normally distributed?

Back

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.

Front

How do you calculate the variance of a dataset?

Back

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