Hi, I was wondering if someone could help me with my assignment. Now that you ha
ID: 3041701 • Letter: H
Question
Hi, I was wondering if someone could help me with my assignment.
Now that you have used descriptive statistics and examined the data numerically and also graphically, you are ready to begin answering your research questions using inferential statistics. Descriptive statistics describe the data in the sample, while inferential statistics allows one to take those results and hopefully make inferences about the population from which the sample was drawn. To do this, one must perform hypothesis testing.
In this assignment, you will define the steps needed to evaluate the continuous response and continuous explanatory variable research question and perform the appropriate hypothesis test with Stata. Make sure you explicitly show all five steps and consider any necessary assumptions that were discussed in the lecture.
These steps are:
Define the parameter of interest
State the hypotheses
Determine the test statistic and p-value considering any necessary assumptions
Decide whether to reject or not reject the null hypothesis
Clearly state a conclusion in the context of the problem
For example, suppose we have collected data from 50 subjects on the average number of hours slept per night and the average number of days per week of 20+ minutes of moderate exercise. We are interested in seeing if there is any relationship between hours slept and number of exercise days.
The 5-steps would be as follows:
Parameter of interest: Population correlation between the average number of hours slept per night and the number of days the subjects participated in 20+ minutes of moderate exercise. (Note: population correlation is the appropriate parameter of interest as our two variables are continuous)
Hypothesis: H0: = 0; HA: not = 0
Test statistic: I may not get a test statistic with Stata, but it can be calculated to be 2.02 for this data. The p-value is 0.048 and I have 48 degrees of freedom. I should check my scatter plot to test if it looks roughly linear as that is an assumption, and if it does not note that here.
Decision: Since the p-value is less than my alpha level of .05, I reject the null hypothesis of no correlation.
Conclusion: I conclude that the correlation is significantly different (and larger) than 0. In the context of my research question, there is a moderately weak but statistically significant correlation between average hours slept and days per week of moderate exercise.
Your submission needs to clearly discuss each step to properly evaluate your primary research question. You should divide up your document with subheadings for each step. Be sure to restate your research questions at the beginning of your assignment.
My correlation is Population correlation between low birth weight (categorical-dichotomous) in the study and the weight of the mother (continuous ratio)in the study.
Data information:
The data were collected at Bay State Medical Center, Springfield, MA, during 1996. The goal of this case control study was to identify risk factors associated with giving birth to low birth weight babies (weighing less than 2500 grams). The data includes the birth weight (in grams) of 189 newborn babies, 59 of whom had low birth weight and 130 of whom had normal birth weight, along with some characteristics (e.g., age, smoking status) of their mothers.
Variable Codebook
Variable Name
Description
Coding Details/Range
ID
Unique identifier for each participant
1-250
LOW BIRTH WT
Indicator of low birth weight (defined as < 2,500 grams)
0 = No, 1 = Yes
AGE OF MOTHER
Mother’s age, years
14-45
WT OF MOTHER
Mother’s weight at last menstrual cycle, pounds
80-250
RACE OF MOTHER
Race of mother
1 = White, 2 = Black,
3 = Other
SMOKING STATUS DURING PREGNANCIES
Indicator of smoking status
0 = No, 1 = Yes
NUMBER PREVIOUS PREMATURE LABORS
Number of previous premature labors
0-3
HX OF HYPERTENSION
Indicator of history of hypertension
0 = No, 1 = Yes
PRESENCE OF UTERINE IRRITABILITY
Indicator of presence of uterine irritability
0 = No, 1 = Yes
NUMBER PHYSICIAN VISITS FIRST TRIMESTER
Number of physician visits during the first trimester of the pregnancy
0-6
BIRTH WT
Baby’s birth weight, grams
700-5000
Variable Name
Description
Coding Details/Range
ID
Unique identifier for each participant
1-250
LOW BIRTH WT
Indicator of low birth weight (defined as < 2,500 grams)
0 = No, 1 = Yes
AGE OF MOTHER
Mother’s age, years
14-45
WT OF MOTHER
Mother’s weight at last menstrual cycle, pounds
80-250
RACE OF MOTHER
Race of mother
1 = White, 2 = Black,
3 = Other
SMOKING STATUS DURING PREGNANCIES
Indicator of smoking status
0 = No, 1 = Yes
NUMBER PREVIOUS PREMATURE LABORS
Number of previous premature labors
0-3
HX OF HYPERTENSION
Indicator of history of hypertension
0 = No, 1 = Yes
PRESENCE OF UTERINE IRRITABILITY
Indicator of presence of uterine irritability
0 = No, 1 = Yes
NUMBER PHYSICIAN VISITS FIRST TRIMESTER
Number of physician visits during the first trimester of the pregnancy
0-6
BIRTH WT
Baby’s birth weight, grams
700-5000
Explanation / Answer
You have not given any data for this question , however the exact steps and the hypothesis set up can be as follows
Parameter of interest: whether the low birth weight of the child is related to the weight of the mother
Hypothesis:
H0: Low birth weight is not related to the weight of the mother
HA: Low birth weight is significantly related to the weight of the mother
Test statistic:
This would be a case of difference in the mean weight of the mother, the data is with unequal samples .
as 59 had normal birth weight and 130 had low birth rate
so we can use the z test as follows
where x1bar and x2bar are the mean values of the 2 groups
sigma1 and sigma2 are the standard deviation
and n1 and n2 are the sample sizes
after calculating the z stat , check for the p value in the z table
Decision: if the p-value is less than my alpha level of .05, then reject the null hypothesis in favor of altermate hypothesis
Conclusion :
as we reject the null hypothesis , hence we conclude Low birth weight is significantly related to the weight of the mother
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