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Statistics, Data, and Probability I: Drill Set 3, Problem 4. How many different avatars can be created based on the given options?
Statistics, Data, and Probability II Drill 3 Problem 2. Which two sports together make up for the preferences of more than half of all those w...
SAT Math 4.1 Statistics and Probability 243 Views
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Description:
SAT Math 4.1 Statistics and Probability
Transcript
- 00:03
Here’s your shmoop du jour, brought to you by Math Tests.
- 00:06
Sometimes, your teachers grade them on a Sine Curve.
- 00:11
On his last four tests, Ted scored a 71, 86, 77, and 92.
- 00:17
What must he score on his fifth test to have an arithmetic mean of at least 85?
- 00:28
He’s looking for the arithmetic mean;
Full Transcript
- 00:30
remember, that's the sum of the data divided by the number of data entries.
- 00:35
It's another name for the AVERAGE.
- 00:43
To find out what Ted must score on his fifth test—we'll call it variable T—to have
- 00:48
an arithmetic mean of at least 85, we can write an equation as follows.
- 00:52
85 equals the sum of all the tests: 71 plus 86 plus 77 plus 92 plus T divided by 5.
- 01:03
Let's solve for T now. We start by multiplying both sides by 5.
- 01:07
We get 85 times 5 is 425. Adding up 71, 86, 77 and 92 equals 326 plus T.
- 01:15
Subtract 326 from both sides...and we get T equals 99.
- 01:20
So 99 is our answer. Yikes. Happy cramming, Ted…
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