Chapter 5 test

Front

What percentage of data falls within 1 standard deviation according to the empirical rule?

Back

68%

Front

If the ages of golfers are normally distributed with a mean of 38 and a standard deviation of 4, how many out of 500 members are younger than 34?

Back

80

Front

What percent of students have a GPA between 2.9 and 3.8 if the mean GPA is 3.2 with a standard deviation of 0.3?

Back

81.5%

Front

If the average waist size for teenage males is 29 inches with a standard deviation of 1.4 inches, what proportion of teenagers have waist sizes greater than 31 inches?

Back

7.6%

Front

What is the total area under the standard normal distribution curve?

Back

1

Front

Define the empirical rule in statistics.

Back

The empirical rule states that for a normal distribution, approximately 68% of the data falls within 1 standard deviation of the mean, 95% within 2 standard deviations, and 99.7% within 3 standard deviations.

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 than data far from the mean.

Front

What does standard deviation measure?

Back

Standard deviation measures the amount of variation or dispersion of a set of values.

Front

What is the mean in a data set?

Back

The mean is the average of all the data points in a set, calculated by dividing the sum of all values by the number of values.

Front

How do you calculate the z-score?

Back

The z-score is calculated by subtracting the mean from the value and then dividing by the standard deviation: z = (X - μ) / σ.