Statistical Terms, Factorials, & Perfect Squares

Averages

like ratios, proportions, and rates, use fractions to find the answer to a problem period here is the average formula: Average= Sum of the Terms / Number of the terms *can be rearranged*

Mean

is the same as average and is calculated the same way.

Range

is how wide the group of numbers is and can be calculated by subtracting the smallest number from the largest.

Mode

is the number that appears most frequently

Median

Is the middle value of a group of numbers.*a situation whereby there are two numbers in the middle, the average of those two middle numbers is the median*

Sequence

merely a group of numbers placed in order. you may experience a sequence called arithmetic sequence on the test. The property that creates an arithmetic sequence is that each number is equal to the number before it plus a constant number.

Mean=Median when numbers are in arithmetic sequence.

Factorials

A integer followed by an (!) the product of the integer the factorial sign and all the positive integers below it.
Example:
7!= 7*6*5*4*3*2*1

*If ever given a fraction w/ factorials, there's often cancelling out*

13*13

169

14*14

196

15*15

225

16*16

256

17*17

289

18*18

324

19*19

361

20*20

400

21*21

441

22*22

484

23*23

529

24*24

576

25*25

625