Five years ago mean age of a family was 25 years. What is the present mean age of the family?
1 answer:
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Answer:
a)Slope:
Intercept:
b)
And the determination coeffecient is
Step-by-step explanation:
Data given and definitions
The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.
The sum of squares "is the sum of the square of variation, where variation is defined as the spread between each individual value and the grand mean"
When we conduct a multiple regression we want to know about the relationship between several independent or predictor variables and a dependent or criterion variable.
n=110,
Part a
The slope is given by this formula:
If we replace we got:
We can find the intercept with the following formula
We can find the average for x and y like this:
And replacing we got:
Part b
In order to calculate the correlation coefficient we can use this formula:
For our case we have this:
n=110,
So we can find the correlation coefficient replacing like this:
And the determination coeffecient is