Normal Distribution

Front

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

Back

1

Front

What percentage of data falls within one standard deviation of the mean in a normal distribution?

Back

Approximately 68%.

Front

What is the mean and standard deviation if 68% of the marks in a test are between 51 and 64?

Back

Mean = 57.5, S.D. = 6.5.

Front

What is the average waist size for teenage males if the mean is 29 inches and the standard deviation is 1.4 inches?

Back

Mean = 29 inches, S.D. = 1.4 inches.

Front

How do you estimate the proportion of teenagers with waist sizes greater than 31 inches if the average waist size is 29 inches with a standard deviation of 1.4 inches?

Back

Approximately 7.6%.

Front

What is NOT true about the standard normal distribution?

Back

It is asymmetrical.

Front

What is the mean and standard deviation of a test where students pass if they score 50% or more, with a mean of 42% and a standard deviation of 8%?

Back

Mean = 42%, S.D. = 8%.

Front

What percentage of students pass the test if the mean is 42% and the standard deviation is 8%?

Back

Approximately 16%.

Front

What is the empirical rule in statistics?

Back

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

Front

What is a z-score in the context of normal distribution?

Back

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