Hypothesis Test for a claim about the proportion p
When
n·q and
n·p are both greater than 5, the binomial distribution is approximated by the standard normal distribution (
z distribution).
To find the critical value of z for confidence intervals, compute α ÷ 2 and look up the associated value of z in the standard normal distribution (Table A-2). The critical value is negative for left tail tests, positive for right tail tests. For two tailed tests there are two critical values, one postive and the other negative.
Sample proportion
Definition of q
Test Statistic
Remember to look at the null hypothesis to find the hypothesized value of the population proportion p