Question

13.34 you are studying the relationship between history of early childhood trauma (categorized as trauma/no trauma) and weight in adulthood (categorized as low to normal, overweight, and obese). Past research has suggested that those children who experienced trauma (such as child abuse) are more likely to develop weight problems in adulthood. You calculated a Chi-square of 18.26. You can decide to ____________ the Null Hypothesis at p<.05.

13.35 Professor Miller samples 500 high school students for a study on alcohol use, and wants to ensure that her sample is racially representative of all students in New York State, her population of interest. She will need to be able to _______________ the Null Hypothesis of goodness of fit in order to continue on with her research.

13.38 A large outpatient medical clinic has hired a program evaluator to assist them in planning new services for immigrants with language barriers, such as translators. They have selected a sample of 520 recent patients with identified language barriers on their most recent medical records. Based upon all existing records of patients with language barriers, they expect to find the following proportions: 21% (.21) who have a mild language barrier; 42% (.42) who have a moderate language barrier; and 37% (.37) with a severe barrier. Using the formula for expected values for Goodness of Fit tests, calculate the expected value for those with a severe barrier

13.39 A large outpatient medical clinic has hired a program evaluator to assist them in planning new services for immigrants with language barriers, such as translators. They have selected a sample of 520 recent patients with identified language barriers on their most recent medical records. Based upon all existing records of patients with language barriers, they expect to find the following proportions: 21% (.21) who have a mild language barrier; 42% (.42) who have a moderate language barrier; and 37% (.37) with a severe barrier. If you were to conduct a Goodness of Fit test, how many degrees of freedom would you have?

Answer 1

13.34

The degrees of freedom (DF) is equal to: DF = (r - 1) * (c - 1) where r and c are the factors of variables - history of early childhood trauma and weight in adulthood respectively.

r = 2 and c = 3

DF = (2-1) * (3-1) = 2

P-value = P( > 18.26, DF = 2) = 0.0001 which is less than the significance level of 5%. Thus,

You can decide to _____reject_______ the Null Hypothesis at p<.05.

13.35

Null hypothesis of goodness of fit test is,

The data are consistent with a specified distribution.

She needs to be sure that her sample is racially representative of all students in New York State

So, She will need to be able to ___accept____________ the Null Hypothesis of goodness of fit in order to continue on with her research.

13.38

Expected value for those with a severe barrier = n * p = 520 * 0.37 = 192.4

where n is the sample size

and p is proportion of patients with a severe barrier

13.39

degrees of freedom = Number of levels of categorical variable language barrier - 1

= 3 - 1 = 2