# Finding statistic, critical value and p value: Example problem

Suppose a study is constructed to test a claim, at a 0.05 significance level that a population proportion is 40%.

A simple random sample of 750 subjects has a proportion of 42%.

Determine the test statistic, critical value z = + or -, determine the p value.

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#### Solution Preview

Find statistic, critical value and p value

Suppose a study is constructed to test a claim, at a 0.05 significance level that a population proportion is 40%.

A simple random sample of 750 subjects has a proportion of 42%.

Determine the test statistic, critical value z = + or -, determine the p value.

Let be the unknown population proportion.

The estimate of is the sample proportion .

0.420 (Where 315, and 750)

The null and alternative hypotheses:

0.40

0.40

The test statistic:

1.12 ( 0.42, 0.40, and ...

#### Solution Summary

The solution tests a claim at 0.05 significance level. The test statistic and p-value is determined.