Stats Test 3 Review

Front

What is a correlation coefficient?

Back

A statistical measure that describes the strength and direction of a relationship between two variables, ranging from -1 to 1.

Front

What does a correlation coefficient close to zero indicate?

Back

It indicates a weak or no linear relationship between the two variables.

Front

What effect does changing the units of measurement have on correlation?

Back

No Change; correlation is a unitless measure.

Front

What is the shape of a distribution for salaries in a city?

Back

Skewed Right; typically, a few high salaries pull the mean to the right.

Front

What percent of scores fall within one standard deviation of the mean in a normal distribution?

Back

Approximately 68%.

Front

What is the formula to calculate an index number?

Back

Index Number = (Current Value / Base Value) x 100.

Front

If the mean is 100 and the standard deviation is 20, what is the range for one standard deviation?

Back

80 to 120.

Front

What does a skewed right distribution indicate about the data?

Back

It indicates that there are a few high values that are pulling the mean to the right.

Front

What is the empirical rule in statistics?

Back

In a normal distribution, about 68% of data falls within one standard deviation, 95% within two, and 99.7% within three.

Front

How do you interpret an index number of 146 for gasoline prices?

Back

It means that gasoline prices in April 2022 were 46% higher than in the base year (2019).