In 1997, 4% of pregnant women nationally reported smoking more than 20 cigarettes (a "pack") during the course of their pregnancy. An obstetrician believes that this proportion has since decreased, with the increase in awareness about the dangers of smoking. To test this, they obtain patient records from 154 randomly selected pregnancies, and find only 3 women who reported smoking more than a pack of cigarettes over the course of their pregnancy. Use the normal approximation test of proportions to test the obstetrician's hypothesis, at the α = 0.10 level of significance.
np0(1-p0) = ? (Round to 3 decimal places.)
The normal approximation test for proportions is appropriate for this data.
To test the given hypotheses, we will use a two-tailed test. The appropriate critical value(s) for this test is/are?
The sample proportion is p^ = (Round to 3 decimal places.)
The test statistic for this test is ? (rounded to 3 decimal places.)
We fail to reject H0.
The given data does not provide significant evidence that the proportion of pregnant women who report smoking more than a pack of cigarettes during the course of their pregnancy has decreased since 1997.
The P-value for this test is (Do not round.)
Recall that when conditions for the normal approximation test are not satisfied, the Fisher's Exact test for proportions is instead more appropriate.
Use Minitab to compute the P-value for the previous test, this time using the Exact method. The exact P-value for this test is (Do not round.)
At level of significance α = 0.10, we fail to reject H0.
The given data does not provide significant evidence that the proportion of pregnant women who report smoking more than a pack of cigarettes during the course of their pregnancy has decreased since 1997.