Normal distribution

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 shape is a normal distribution curve?

Back

Bell curve.

Front

What is the total area under the normal distribution curve?

Back

1.

Front

According to the empirical rule, what percentage of data falls within 1 standard deviation of the mean?

Back

68%.

Front

According to the empirical rule, what percentage of data falls within 2 standard deviations of the mean?

Back

95%.

Front

According to the empirical rule, what percentage of data falls within 3 standard deviations of the mean?

Back

99.7%.

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 does a z-score represent?

Back

A z-score represents the number of standard deviations a data point is from the mean.

Front

What is the area under the curve between z = 0 and z = 1.45?

Back

0.4265.

Front

What is the probability of x < 13 if the mean is 10 and variance is 4?

Back

0.9332.