FLASHCARD: Normal Distribution and Measures of Dispersion

Front

What is the mean of a data set?

Back

The mean is the average of a set of numbers, calculated by adding all the numbers together and dividing by the count of numbers.

Front

How do you calculate the mean of the numbers: 5, 11, 2, 12, 4, 2?

Back

Mean = (5 + 11 + 2 + 12 + 4 + 2) / 6 = 36 / 6 = 6.

Front

What is a z-score?

Back

A z-score indicates how many standard deviations an element is from the mean of a data set.

Front

Calculate the z-score for a data set with a mean of 290 and a standard deviation of 20 for the value 265.

Back

z = (265 - 290) / 20 = -25 / 20 = -1.25.

Front

What is standard deviation?

Back

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

Front

Calculate the standard deviation for the data set: {12, 13, 29, 18, 61, 35, 21}.

Back

Standard deviation = 17.14.

Front

What is the range of a data set?

Back

The range is the difference between the highest and lowest values in a data set.

Front

Find the range of Roger's bowling scores: 155, 165, 138, 172, 127, 193, 142.

Back

Range = 193 - 127 = 66.

Front

What is a normal distribution?

Back

A normal distribution is a probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence.

Front

True or False: The normal curve is symmetrical about the mean.

Back

True.