Understanding the Standard Normal Distribution

The video tutorial provides an overview of the standard normal distribution, focusing on z-scores. It explains that a z-score represents the number of standard deviations a data value is from the mean. The standard normal distribution has a mean of zero and a standard deviation of one. The tutorial covers how to determine z-scores for data values below and above the mean, and clarifies that the mean itself has a z-score of zero.

What is a z-score?

• A type of probability distribution

• The number of standard deviations a data value is from the mean

• A measure of central tendency

• A measure of data spread

What is the mean of the standard normal distribution?

• Varies with standard deviation

• 0

• Depends on the data

• 1

What is the standard deviation of the standard normal distribution?

• 1

• 0

• Varies with mean

• Depends on the data

If a data value is 0.8 standard deviations below the mean, what is its z-score?

• 0.8

• -1.8

• -0.8

• 1.8

What does a negative z-score indicate?

• The data value is at the maximum

• The data value is at the mean

• The data value is below the mean

• The data value is above the mean

If a data value is 1.9 standard deviations above the mean, what is its z-score?

• -1.9

• 1.9

• -0.9

• 0.9

What does a positive z-score indicate?

• The data value is at the mean

• The data value is below the mean

• The data value is at the minimum

• The data value is above the mean

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

• 1

• 0

• Depends on the data

• -1

Where is the mean located in a normal distribution?

• At the center

• At the peak

• At the right tail

• At the left tail

What does a z-score of zero indicate?

• The data value is at the mean

• The data value is above the mean

• The data value is below the mean

• The data value is at the maximum