Stats

What is Standard Deviation?

• A measure of central tendency

• A measurement of how much data varies

• A measurement of how much data varies from the average

What's the standard deviation?

• 150

• 60

• 240

• 30

What shape is a normal distribution curve?

• Half curve

• Round curve

• Bell curve

• Square curve

The z-score represents.....

• the amount of standard deviations a data value is above or below the mean.

• the percentile the data value is above or below the mean.

• the amount of standard deviations a data value is above or below the median.

• the percent the data value is above or below the mean.

What is the z-score for the mean?

• -1

• +1

• 0

• It doesn't have one!

If I have a positive z-score, I scored ABOVE or BELOW the mean?

• ABOVE

• BELOW

Joanne's Z-score is -1.5. What does this mean?

• She didn't take the test yet.

• She scored 1.5 standard deviations below the average.

• She did better than most people.

• No clue

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days.

About what percent of the products last 6 days or less?

• 68%

• 34%

• 16%

• 2.5%

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days.

About what percent of the products last between 12 and 15 days?

• 68%

• 34%

• 16%

• 2.5%

What is the standard deviation for the data given:

• 6.89

• 10.1

• 7.26

• 9