ShmoopTube

00:04

Here's your shmoop du jour brought to you by z-scores

00:07

their how a Frenchman tells you z-score of z-game okay here's our question.. Ella [Frenchman stood in front of Eiffel Tower]

00:12

receives a 92 on her algebra test the average score was 82 with a standard

00:17

deviation of 10 her z-score is what and here are the potential answers

00:23

Believe it or not a z-score does exist outside of the French [Frenchman and people playing sports in the background]

00:28

sporting culture a z-score can be used when you want to standardize scores and

00:32

compare them to the average well they also allow you to determine how many

00:36

standard deviations each z-score is from the mean or central tendency and just as

00:42

a refresher because who doesn't like refreshments a standard deviation is a [Students eating refreshments]

00:46

measure used to quantify the amount of variation within a set of data in this

00:51

case how much variation there is between test scores okay now that we've

00:55

refreshed our brains and we're ready to go let's take a look at our question to

00:59

find a z-score you divide the difference of a data point and the mean by the [Man inspecting answer choices]

01:03

standard deviation so it'll look sort of like this all we

01:06

have to do now is fill in the equation our data point of interest is 92 and we

01:10

know our mean is 82 and our standard deviation is... sorry 10....

01:17

well a little mathematical magic and boom our answer is A - 1...Pretty cool [Magician uses wand and firework appears]

01:22

trick Mathemagician, wish we could have hired you when we were in school

Full Transcript