Stats

Question 1

Numbers of Integers in a set

Answer 1

Includes first and last = High - Low + 1
Includes only 1 end point = High - Low
Includes none of the end points = High - Low - 1

If you need to find evens or odds, # terms = [(High - Low)/2]+1

If you need to find multiples = (High-Low)/Common difference +1

Question 2

Finding the Average of an Evenly Spaced Set

Answer 2

If the set is evenly spaced the average is = (High + Low)/2. This formula applies to all evenly spaced sets (i.e. multiples of 2, 3, 4, etc).

Question 3

Finding Medians of Large Sets

Answer 3

If the set has odd # of terms. The median will be at the (n+1)/2 position
If the set has even # of terms. The median is the average of the values at n/2 & (n+2)/2 positions.

Question 4

Standard Deviation

Answer 4

If a constant is added/substracted to all terms in a set, the SD does not change. You can have data sets with the same SD but different avgs.

If a constant is multiplied/divided to all terms in a set, the SD will be multiplied by that amount.

Question 5

Estimating Standard Dev

Answer 5

1. Find the average of the set
2. Find the absolute delta from from each point to the mean
3. Sum all the deltas. Compare sets.