7 results

correlation - a statistical measure that expresses the extent to which two variables are linearly related

A professor assumed there was a correlation between the amount of hours people were expose to sunlig

A professor assumed there was a correlation between the amount of hours people were expose to sunlight and their blood vitamin D level. The null hypothesis was that the population correlation was__
a. Positive 1.0
b. Negative 1.0
c. Zero
d. Positive 0.50
[B]c. Zero[/B]
Reason: Since the professor wanted to assume a correlation (either positive = 1.0 or negative = -1.0), then we take the other side of that assumption for our null hypothesis and say that there is no correlation (Zero)

Covariance and Correlation coefficient (r) and Least Squares Method and Exponential Fit

Free Covariance and Correlation coefficient (r) and Least Squares Method and Exponential Fit Calculator - Given two distributions X and Y, this calculates the following:

* Covariance of X and Y denoted Cov(X,Y)

* The correlation coefficient r.

* Using the least squares method, this shows the least squares regression line (Linear Fit) and Confidence Intervals of α and Β (90% - 99%)

Exponential Fit

* Coefficient of Determination r squared r^{2}

* Spearmans rank correlation coefficient

* Wilcoxon Signed Rank test

* Covariance of X and Y denoted Cov(X,Y)

* The correlation coefficient r.

* Using the least squares method, this shows the least squares regression line (Linear Fit) and Confidence Intervals of α and Β (90% - 99%)

Exponential Fit

* Coefficient of Determination r squared r

* Spearmans rank correlation coefficient

* Wilcoxon Signed Rank test

Fisher Transformation and Fisher Inverse

Free Fisher Transformation and Fisher Inverse Calculator - Given a correlation coefficient (r), this calculates the Fisher Transformation (z).

Given a Fisher Transformation (r), this calculates the Fisher Inverse (r)

Given a Fisher Transformation (r), this calculates the Fisher Inverse (r)

If the correlation between two variables is close to minus one, the association is: Strong Moderate

If the correlation between two variables is close to minus one, the association is:
Strong
Moderate
Weak
None
[B]Strong[/B] - Coefficient near +1 or -1 indicate a strong correlation

In simple linear regression the slope and the correlation coefficient will have the same signs True

In simple linear regression the slope and the correlation coefficient will have the same signs
True
False
[B]FALSE[/B] - Only if they are normalized

The coefficient of determination is found by taking the square root of the coefficient of correlatio

The coefficient of determination is found by taking the square root of the coefficient of correlation. True or False
[B]FALSE[/B] - It is found by squaring the coefficient of correlation

What is the range of possible values for a coefficient of correlation?

What is the range of possible values for a coefficient of correlation?
[B]The range is -1.0 to +1.0[/B]