Module 18: Statistics

Question 1

Average of terms (formula)

Answer 1

Sum of terms / count of terms

Question 2

Count of terms(formula)

Answer 2

Sum of terms / average of terms

Question 3

Sum of terms (formula)

Answer 3

Count of terms * Average of terms

Question 4

Number of consecutive integers in a set

Answer 4

Remember that it’s usually inclusive!

Highest value - Lowest value + 1

Question 5

Counting Consecutive Multiples in a set

Answer 5

[(Highest multiple - Lowest multiple) / Factor value] + 1

If one end is not inclusive: don’t add 1.
If neither end is inclusive: subtract 1

Question 6

Average of an evenly spaced set

Answer 6

(First + Last)/2

Question 7

Weighted Averages formula

Answer 7

Sum of Weighted Terms / Total # of Weighted Terms

Question 8

The mean is equal to the median if ___

Answer 8

we have an evenly spaced set of numbers

Question 9

Mode (definition & 2 catches)

Answer 9

the number that appears most frequently in a dataset.

• If there is a tie, then there can be more than one mode.
• If each number in the set occurs the same number of times as the others, the set has no mode.

Question 10

Range (definition)

Answer 10

Highest value in set - Lowest value in set

Question 11

Standard Deviation threshold formula

Answer 11

High: mean + x(sd) (where X = # of stdevs)
Low: mean - x(sd)

Question 12

Approximating Standard Deviation of a set - 3 steps

Answer 12

1) Find mean of each set
2) Determine the difference (in absolute value) between each value in the set & the mean
3) Sum the absolute differences
4) Divide sum from #3 by count of values in set (not needed if the # of values in each set are equal)

Question 13

Formula Logic: Determine the factor by which a formula’s result has changed (steps)

Answer 13

Divide the new formula (numerator) by the old formula (denominator.) Simplify double-decker fractions by inverting & multiplying as needed.

Remember: NEWmerator