Normal Distribution

Front

What shape is a normal distribution curve?

Back

Bell curve

Front

What is the z-score formula?

Back

z = (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

Front

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

Back

Approximately 68%.

Front

What percentage of data falls within two standard deviations of the mean in a normal distribution?

Back

Approximately 95%.

Front

What percentage of data falls within three standard deviations of the mean in a normal distribution?

Back

Approximately 99.7%.

Front

If the mean temperature is 23 degrees and the standard deviation is 4.2 degrees, what is the z-score for a temperature of 17 degrees?

Back

-1.43

Front

If the average waist size for teenage males is 29 inches with a standard deviation of 2 inches, what is the z-score for a waist size of 33 inches?

Back

2

Front

What is the mean and standard deviation of the shelf life of a dairy product if it is normally distributed with a mean of 12 days and a standard deviation of 3 days?

Back

Mean = 12 days, Standard Deviation = 3 days.

Front

If the mean life of a tire is 30,000 km and the standard deviation is 2000 km, what is the range for 68% of all tires?

Back

28,000 km and 32,000 km.

Front

What is a z-score and what does it represent?

Back

A z-score indicates how many standard deviations a data point is from the mean.