Mathematics · Grades 6–8
Statistics & probability · Formula sheet
Rules, conditions and small examples in one printable reference.
Remember this
Range of a data set
Sort the data or find its two extreme values.
range = maximum − minimum
141 − 42 = 99
Complementary probability
An event and its complement cover all outcomes without overlap.
P(not A) = 1 − P(A)
1 − 8/20 = 3/5
Two draws with replacement
Replacing the first item keeps the second probability unchanged.
P(A then A) = P(A)²; independent draws
5/11 × 5/11 = 25/121
Interquartile range
Use medians of the lower and upper halves for this exercise.
IQR = Q₃ − Q₁
Q₁ = 50.5; Q₃ = 94.5; IQR = 44
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · teacher review required. Grade bands are approximate, not official curriculum alignment.