Sample Size for Margin of Error of a Proportion Calculator
Compute the minimum sample size needed for a desired margin of error E around a proportion p̂ at a given confidence leve...
Compute the minimum sample size needed for a desired margin of error E around a proportion p̂ at a given confidence leve...
Fit an ordinary least-squares regression line to two equal-length lists of numbers and report slope, intercept, r, and r...
Compute the Pearson chi-square goodness-of-fit statistic from up to six (observed, expected) pairs: χ² = Σ (O − E)² / E....
Compute sin(A+B), cos(A+B), and tan(A+B) from two angles A and B (in degrees), using the angle-addition identities sin(A...
Compute the mean of grouped data from up to six (midpoint, frequency) pairs: x̄ = Σ(fᵢ · xᵢ) / Σfᵢ.
Compute the gravitational potential energy of an object from its mass, height above a reference level, and the local gra...
Compute Pearson's product-moment correlation r directly from streaming sums Σx, Σy, Σxy, Σx², Σy², and sample size n. r...
Compute the equation of the plane passing through three 3-D points P, Q, R. The normal vector is the cross product (Q −...
Compute a weighted average from two equal-length lists of values and weights — useful for grades, weighted survey scores...
Project a quantity that grows continuously at a constant rate r over time t, using the standard exponential growth model...
Calculates hydraulic power (useful power delivered to fluid) and shaft power input from fluid density, flow rate, pump h...
Calculates engineering stress σ = F/A, the percentage elongation to failure, and the reduction in area for a tensile tes...
Every "X% of Y" problem, every "what percent of", every percent-change question — written out the way you'd actually say them.
Standard deviation is "average distance from the average". That one sentence covers 90% of everything you ever need to remember about it.