Probability assay II

ParameterValue for indicated portion of log phase
Cell density (cells/ml)a2 × 106–3 × 1062 × 107–3 × 1071 × 108
No. of tubes with motile spirochetes0012
No. of tubes with nonmotile spirochetes222231
No. of tubes with motile spirochetes/total no. of tubes0/220/2212/43
% of tubes with motile spirochetes0028
Statistical significance (chi-squared with Yates's continuity correction)Early vs mid, nullMid vs late (approximation), P = 0.0162Early vs late (approximation), P = 0.0162
  • a Density to which cells were grown.