$$ s = \sqrt\frac\sum(x_i - \barx)^2n - 1 $$
[ \fracdNdt = rN \left(1 - \fracNK\right) ] ap bio formula sheet
| | Formula | |--------------|--------------| | Compare data spread | Standard deviation | | Is observed ratio different from expected? | Chi-square | | Find heterozygous frequency in population | 2pq (from H-W) | | Water movement into/out of cell | Water potential Ψ | | Why cells stay small | SA/V ratio | | Dilute a stock solution | C₁V₁ = C₂V₂ | | Error bars on graph | SE = s/√n | $$ s = \sqrt\frac\sum(x_i - \barx)^2n - 1