This GeoGebra activity shows four different [i]means[/i] of two values [color=#0000ff][i]a[/i][/color], [color=#ff0000][i]b[/i][/color]:[br][color=#b20ea8][i]- AM [/i]= arithmetic[/color], [color=#198f88][i][br]- GM[/i] = geometric[/color], [br]- [color=#0a971e][i]QM[/i] = quadratic[/color][color=#d69210],[i][br]- HM[/i] =harmonic[/color] [br]geometrically.[br][br]The values are dynamically shown as segments on the diameter of a semicircle, and can be modified by moving point X.[br][br]Move point [i]X[/i] to explore the means of [i]a[/i] and [i]b[/i], and explore the inequality [br][math]QM\left(a,b\right)\ge AM\left(a,b\right)\ge GM\left(a,b\right)\ge HM\left(a,b\right)[/math].