A researcher would like to determine if the proportion of households without health insurance coverage differs with household income. Suppose the following data were collected from 700 randomly selected households. Complete parts a through c.
|Less than $25,000||52||23|
|$25,000 to $49,999||143||40|
|$50,000 to $74,999||200||35|
|$75,000 or more||177||30|
a. Using a=0.01, perform a chi-square test to determine if the proportion of households without health insurance differs by income bracket.
i. State the null hypothesis
ii. What is the test statistic?
iii. What is the critical value?
iv. State the conclusion.