La calcolatrice troverà le probabilità semplici e cumulative, nonché la media, la varianza e la deviazione standard della distribuzione ipergeometrica.
Risposta Media: μ = n K N = 12 ⋅ 15 20 = 9 \mu = n \frac{K}{N} = 12 \cdot \frac{15}{20} = 9 μ = n N K = 12 ⋅ 20 15 = 9 A .
Varianza: σ 2 = n K N N − K N N − n N − 1 = 12 ⋅ 15 20 20 − 15 20 20 − 12 20 − 1 = 18 19 ≈ 0.947368421052632. \sigma^{2} = n \frac{K}{N} \frac{N - K}{N} \frac{N - n}{N - 1} = 12 \cdot \frac{15}{20} \frac{20 - 15}{20} \frac{20 - 12}{20 - 1} = \frac{18}{19}\approx 0.947368421052632. σ 2 = n N K N N − K N − 1 N − n = 12 ⋅ 20 15 20 20 − 15 20 − 1 20 − 12 = 19 18 ≈ 0.947368421052632. A
Deviazione standard: σ = n K N N − K N N − n N − 1 = 12 ⋅ 15 20 20 − 15 20 20 − 12 20 − 1 = 3 38 19 ≈ 0.973328526784575. \sigma = \sqrt{n \frac{K}{N} \frac{N - K}{N} \frac{N - n}{N - 1}} = \sqrt{12 \cdot \frac{15}{20} \frac{20 - 15}{20} \frac{20 - 12}{20 - 1}} = \frac{3 \sqrt{38}}{19}\approx 0.973328526784575. σ = n N K N N − K N − 1 N − n = 12 ⋅ 20 15 20 20 − 15 20 − 1 20 − 12 = 19 3 38 ≈ 0.973328526784575. A
P ( X = 8 ) ≈ 0.255417956656347 P{\left(X = 8 \right)}\approx 0.255417956656347 P ( X = 8 ) ≈ 0.255417956656347 A
P ( X < 8 ) ≈ 0.051083591331269 P{\left(X \lt 8 \right)}\approx 0.051083591331269 P ( X < 8 ) ≈ 0.051083591331269 A
P ( X ≤ 8 ) ≈ 0.306501547987616 P{\left(X \leq 8 \right)}\approx 0.306501547987616 P ( X ≤ 8 ) ≈ 0.306501547987616 A
P ( X > 8 ) ≈ 0.693498452012384 P{\left(X \gt 8 \right)}\approx 0.693498452012384 P ( X > 8 ) ≈ 0.693498452012384 A
P ( X ≥ 8 ) ≈ 0.948916408668731 P{\left(X \geq 8 \right)}\approx 0.948916408668731 P ( X ≥ 8 ) ≈ 0.948916408668731 A