Precision

Probability

Probability, combinatorics & unit converters

Factorial

n!
720

Permutations

nPr
720

Combinations

nCr
120

Simple probability

Probability
0.25
Percent
25%
Odds in favor
1 : 3

Binomial distribution

P(X = k)
0.205078125
P(X ≤ k)
0.376953125
P(X ≥ k)
0.828125
Mean
5
Variance
2.5

Normal distribution

Density f(x)
0.1295175957
P(X ≤ x)
0.933192769
Z-score
1.5

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How to use Precision

Three calculators in one. A quick tour:

  • 1

    Scientific

    Type with your keyboard or tap the keys. Enter evaluates, Esc clears. Switch DEG / RAD / GRAD, use 2nd for inverse functions, and revisit any result from History.

  • 2

    Solver

    Choose an operation — solve, derivative, integral, simplify, expand, factor — then enter an expression such as x^2 - 5x + 6 = 0 and the variable. Tap an example to try it instantly.

  • 3

    Probability & Converter

    Factorials, permutations, combinations, binomial and normal distributions, plus unit conversion across ten categories. Everything recalculates as you type.

  • ★

    Install & offline

    Install Precision for a full-screen app that works without a connection. Use the Install button when it appears, or your browser’s “Add to Home Screen”.