Null hypothesis, alternative hypothesis, statistics

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Therefore, there is a significant difference between the average cholesterol level of college aged men nationwide and male MVCC students. In summary, we conducted a right tailed test at the 1% significance level to determine if there is evidence that the average male MVCC student has higher cholesterol level than the general population. With a sample size of 12 and a sample mean of 195, we calculated a test statistic of 2.5981 and a P-value of 0.00469. As the P-value is less than the significance level, we reject the null hypothesis and conclude that there is evidence of a significant difference between the average cholesterol level of college aged men nationwide and male MVCC students.
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Homework Statement


Assume that the cholesterol level of college aged men nationwide is normally distributed with mean of 180 and standard deviation is 20. Twelve male MVCC students were randomly selected; the cholesterol level of each was determined: 250, 220, 145, 225, 170, 210, 200, 210, 130, 210, 180 and 190. Is there evidence (at the 1% significance level) that the average male MVCC student has higher cholesterol level than the general population?
a.) Identify (using symbols) the null and alternative hypotheses.
b.) Is this a right tailed, left tailed or two-tailed test?
c.) Identify the appropriate distribution; give its mean and standard deviation.
d.) State the formula for the test statistic; substitute the specific values, then calculate the resultant.
e.) Determine the P-value.
f.) What is your decision?
g.) State your conclusion.



Homework Equations


(work shown below)


The Attempt at a Solution



a.) Identify the null and alternative hypotheses:
Ho: There is no evidence that the average male MVCC student has higher cholesterol level than the general population.
H1: There is evidence that the average male MVCC student has higher cholesterol level than the general population.

b.) Is this a right tailed, left tailed or two-tailed test?
Right tailed test because the average male MVCC student has higher cholesterol than the general population.

c.)Identify the appropriate distribution; give its mean and standard deviation.
The distribution of the sample distribution is roughly symmetric with a slight right skew. The mean is 195 and the σ is 34.17.

d.)State the formula for the test statistic; substitute the specific values, then calculate the resultant.
Formula: (x bar - p)/ σ
= 250+220+145+225+170+210+200+210+130+210+130+210+180+190= 2340/12 = 195
(195-180)/5.7735 = 2.5981

e.) Determine the P-value:
P=1-0.9952=0.00469

f.) What is your decision?
P value(0.0048) is less than significance level (.01) therefore I reject the null hypothesis.

g.)State your conclusion.
Because we reject our null hypothesis our conclusion is there is evidence that the average male MVCC student has higher cholesterol level than the general population. The probability that this conclusion was drawn due to random variation is 0.00469.
 

1. What is a null hypothesis?

A null hypothesis is a statement that assumes there is no significant difference or relationship between two variables being studied. It serves as the default hypothesis and is tested against an alternative hypothesis in statistical analyses.

2. What is an alternative hypothesis?

An alternative hypothesis is a statement that assumes there is a significant difference or relationship between two variables being studied. It is typically the hypothesis that a researcher is interested in proving through statistical analysis.

3. What is the purpose of statistical analysis?

The purpose of statistical analysis is to make inferences and conclusions about a population based on data collected from a sample. It involves using mathematical and statistical methods to analyze and interpret data, and to determine the likelihood of the results being due to chance or a true effect.

4. How do you determine which hypothesis to accept?

In statistical analysis, the null hypothesis is rejected if the results of the study provide strong evidence against it. This means that the alternative hypothesis is accepted as the more likely explanation for the observed data. The level of significance, or alpha, is typically used to determine if the results are statistically significant enough to reject the null hypothesis.

5. What is the difference between a one-tailed and two-tailed test?

A one-tailed test is used when a researcher is only interested in determining if there is a significant difference or relationship in one direction. For example, if they are only interested in seeing if a new drug has a positive effect on a disease. A two-tailed test is used when a researcher is interested in determining if there is a significant difference or relationship in either direction. For example, if they want to see if a new drug has either a positive or negative effect on a disease. The choice between one-tailed and two-tailed tests should be determined before the study is conducted.

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