GCSE:Statistics Formula Sheet

GCSE:Statistics Formula Sheet

1. Pearson's Product Moment Correlation

   • r=Sxy÷√(SxxSyy)
     • Sxy= Σxy(ΣxΣy÷n)
     • Sxx=Σx²-(Σx)²÷n
     • Syy=Σy²-(Σy)²÷n

2. Symbols

   • <=Less Than
   • >=More Than
   • ≥ =Grater Than or Equa to
   • ≤= less than or equal to

3. Pie Charts

   • Angle in Pie= Number in Category÷Total Number of Values x 360

4. Frequency Density

   • Frequency Density= Frequency÷ Class width
   • Frequency= Frequency Density x Class Width

5. Mean

   • x̅=∑x÷n or x̅=∑fx÷∑f

6. Standard Deviation

   • √∑fx²÷∑f-x̅

7. Q1,Q2,Q3,IQR

   • Q1=n+1÷4
   • Q2=n+1÷2
   • Q3=Q1+Q2
   • IQR=Q3-Q1
   • Outliers are values that are:>Q1+1.5(Q3-Q1) or <Q1-1.5(Q3-Q1)

8. Index Numbers

   • Value÷VAlue in Base Year x 100
   • Weighted Index Number= ∑(index no. x weight)÷∑wright

9. Probability

   • P of an Event= Number of outcomes matching event÷total number of outcomes
   • P of Something Happening= No. of Times its happened÷ Number of Trials

10. Mean Co-ordinates

    • Mean X Co-Ordinate=∑x÷n
    • Mean Y Co-Ordinate=∑y÷n

11. Equation of the Line

    • y=mx+c
      • m=gradient
      • c= Where the line goes through the y axis

12. Standerdised Value

    • Value-Mean÷Standard Deviation