In: Math
The table below gives the age and bone density for five randomly selected women. Using this data, consider the equation of the regression line, yˆ=b0+b1xy^=b0+b1x, for predicting a woman's bone density based on her age. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant.
Age | 3737 | 3939 | 4040 | 5050 | 6464 |
---|---|---|---|---|---|
Bone Density | 357357 | 347347 | 344344 | 343343 | 336336 |
Step 4 of 6:
Substitute the values you found in steps 1 and 2 into the equation for the regression line to find the estimated linear model. According to this model, if the value of the independent variable is increased by one unit, then find the change in the dependent variable yˆy^.
Step 6 of 6:
Find the value of the coefficient of determination. Round your answer to three decimal places.
The regression equation is defined as,
From the data values,
Age, X | Bone Density, Y | X^2 | Y^2 | X*Y | |
37 | 357 | 1369 | 127449 | 13209 | |
39 | 347 | 1521 | 120409 | 13533 | |
40 | 344 | 1600 | 118336 | 13760 | |
50 | 343 | 2500 | 117649 | 17150 | |
64 | 336 | 4096 | 112896 | 21504 | |
Sum | 230 | 1727 | 11086 | 596739 | 79156 |
The least square estimate of intercept and slope are,
The regression equation is,
Step 4 of 6:
If the age is increased by one unit, then the bone density will decrease by 0.5652 (the slope coefficient gives the value for change in dependent variable for one unit change in independent variable)
Step 6 of 6:
The coefficient of determination value is obtained using the formula,
Where,