Statistics - Hypothesis Testing Projects

NOTE: Assume we are testing at α = 0.05 for all statistical tests Mathias studied hyperactive children.

NOTE: Assume we are testing at α = 0.05 for all statistical tests

Mathias studied hyperactive children. She measured several outcome variables for 31 children after they had completed an intervention program. The variables in the data set are the age of the child (AGE), improvement in attitude (ATT), improvement in social behavior (SOC), and improvement in hyperactivity (HYP). [15]

[DATA: hyper]

Calcul ate the correlation coefficient between age and the other variables and complete the following table . Assume that the data are normally distributed.

Correlation between AGE and…	Correlation coefficient	t-statistic value	p-value
ATT	0.399	2.343	0.026
HYP	0.10	0.541	0.957
SOC	-0.185	-1.014	0.319

Calculate the correlation coefficient between age and the other variables and complete the following table. Assume that the data are not normally distributed.

Correlation between AGE and…	Correlation coefficient	z-statistic value	p-value
ATT	0.472		0.007
HYP	-0.254		0.167
SOC	-0.145		0.435

The data for this problem were collected on a simple random sample of 20 patients with hypertension.

[DATA: SBP]

Find the simple linear regression equation between blood pressure and body weight. (3)

Is this a significant regression? (5)

If someone has a weight of 93.5 kg, what would you predict their blood pressure to be based on the results of this sample? (2)

If we include all of the variables in a multiple regression equation to predict blood pressure, which of the variables would we retain in the final model? Place a check next to each variable that we should keep based on a complete analysis. ( 3 )

	Age
	Weight
	Body surface area
	Duration of hypertension
	Basal pulse
	Stress level

The local health district conducted a workshop for teenagers to educate them about sexually transmitted infections (STIs). For 16 year-olds, 21 attended; for 17 year-olds, 50 attended; for 18 year-olds, 44 attended; and for 19 year-olds, 40 attended.

Is there evidence to suggest that the number of teenagers who attended were equally distributed across the four age groups? (1 0 )

Ho:

Ha:

Test statistic and value:

p-value:

Statistical conclusion:

Written conclusion:

In a study by Xiao and Shi, the effects of cranberry juice in treating and preventing Helicobacter pylori infections was investigated. The researchers compared cranberry juice treatment to the standard of care (amoxicillin, bismuth subcitrate, and metronadazole). After four weeks of treatment, the following results were found.

	Was H. pylori eliminated?
	Yes	No
Standard therapy	8	2
Cranberry juice	2	8

Perform a Fisher’s Exact Test on these data. (10)

Ho: Therapy type is NOT associated with the elimination of H. Pylori

Ha: Therapy type is associated with the elimination of H. Pylori

Test statistic and value: DNA

p-value: 0.023

Statistical conclusion: The p-value is less than the significance level and hence we reject the null hypothesis.

Written conclusion: We have enough evidence to support the claim that Therapy type is associated with the elimination of H. Pylori

The following table shows 200 males classified according to social class and headache status measured over the past 12 months.

	Social Class
Headache group	A	B	C
No headaches	6	30	22
Simple headaches	11	35	17
Unilateral headache	4	19	14
Migraine	5	25	12

Are social class and headache group related based on these data? (10)

Skinner et al. conducted a clinical trial to determine whether treatment with melphalan, prednisone, and colchicine (MPC) is superior to colchicines (C) alone in treating amyloidosis. Fifty were treated with C and 50 with MPC. Eighteen months after the last person was admitted to the trial and six years after the trial began, 44 of those receiving C and 36 of those receiving MPC had died.

Complete the following table. (2)

	Died
	Yes	No
C alone	44	6
MPC	36	14

Compute the relative risk and the 95% confidence interval for relative risk for patients receiving C alone. ( 8 )

Provide an interpretation of these values. (2)

Voskuyl et al. investigated patients with rheumatoid arthritis (RA). The investigators were interested in knowing if vasculitis was associated with development of RA in a group of those with RA compared to a group without RA. The subjects were 207 patients, 169 of which had been diagnosed as having vasculits and 38 patients who did not have the condition. There were 32 patients who had been diagnosed as having both RA and vasculitis and 21 patients who had neither condition.

Complete the following table. (2)

	RA
	Yes	No
Vasculitis positive	32	137
Vasculitis negative	17	21

Compute the odds ratio and the 95% confidence interval for odds ratio for the vasculitis positive patients . (10)

Provide an interpretation of these values. (2)

A study by Gantt examined mathematics proficiency in undergraduate nurses who were being examined to see if they could perform appropriate dosage calculations. Test scores (out of 100) were separated into two groups. The first group was traditional students (18-24 years) and the second group was nontraditional students (25+ years). Owing to the disparate sample sizes, a traditional t-test analysis is not appropriate.

[DATA: dosage]

Perform a Mann-Whitney test on these data to determine if the scores differ statistically between these two group. . (9)

Written conclusion:

Torre et al. investicated serum levels of nitrite in pediatric patients. The data consisted of 10 health controls, 14 seronegativized children, and 7 HIV-1-positive children.

[DATA: nitrite]

Use a Kruskal-Wallis test to determine if the three groups differ. (9)

Price: $21.05

Solution: The downloadable solution consists of 9 pages, 1205 words and 6 charts.
Deliverable: Word Document