Hypothesis test for a 2-group proportion difference

Source: R/statpsych3.R

Computes a continuity-corrected z-test for a difference of population proportions in a 2-group design. A confidence interval for a difference in population proportions is a recommended supplement to the z-test (see ci.prop2).

test.prop2(f1, f2, n1, n2)

Arguments

f1

number of group 1 participants who have the attribute

f2

number of group 2 participants who have the attribute

n1

sample size for group 1

n2

sample size for group 2

Value

Returns a 1-row matrix. The columns are:

  • Estimate - ML estimate of proportion difference

  • z - z test statistic

  • p - two-sided p-value

References

Snedecor GW, Cochran WG (1989). Statistical Methods, 8th edition. ISU University Pres, Ames, Iowa.

Examples

test.prop2(11, 26, 50, 50)
#>  Estimate        z           p
#>      -0.3 2.899726 0.003734895

# Should return:
# Estimate        z           p
#     -0.3 2.899726 0.003734895