Question

An obstetrician wants to learn whether the amount of prenatal care and the wantedness of the pregnancy are associated. She randomly selects 939 women who had recently given birth and asks them to disclose whether their pregnancy was intended, unintended, or mistimed. In addition, they were to disclose when they started receiving prenatal care, if ever. The resulting contingency table is below. Are the requirements for performing a chi-square test of independence satisfied? Provide a rationale for you answer. wantedness_preg mos_preg_prior_care Crosstabulation mos preg prior_care > 5 mos. (or never) <3 mos.3 to 5 mos. 26 36.8 Total 652 41.7 652.0 83 5.3 83.0 204 13.0 204.0 939 60.0 939.0 wantedness preg intended Count 593 Expected Count 573.5 644.7 73.0 169 unintended Count її Expected Count mistimed Count 16 19 11.5 53 53.0 Expected Count 179. Total Count 826 826.0 60 Expected Count For the toolbar, press ALT+F10 (PC) or ALT+FN+F10 (Mac) TTT Arial ▼ 3(12pt) , T. -. -.剛 Click Save and Submit to save and submit. Click Save All Answers to save all answers Save All Answer O Type here to search

Answer 1

$Chi-square=\sum \frac{ \left (O-E \right )^2}{E}=21.36$

The P-value for Chi-square=21.36 for (3-1)(3-1)=4 degree of freedom id 0.0003.

Hence, we can conclude that there is an association relationship between the prenatal care and wantedness of the pregnancy at 0.05 level of significance.