In: Math
Data can be collected and organized as an ordered pair (x, y). The data can be analyzed to determine the type and strength of a correlation and to calculate a regression line in order to make a prediction.
Use the internet to find a data set of ordered pairs. Key terms to search: Free Public Data Sets and Medical Data Sets.
Create a Post:
Introduce your Data Set.
1. Which would be the independent variable, and which would be the dependent variable?
Ans: The independent variable is Age in years and the dependent variable is blood pressure.
2. Without drawing a scatter plot, would you expect a positive, negative or no correlation? Explain.
From the above scatter plot, the increases the value of age
increases the value of blood pressure and vice versa. Hence, the
relationship between age and blood pressure is positive.
Would you categorize your data to have a strong or weak correlation? Why?
Ans: Pearson correlation (r) of Age and Blood pressure is 0.896 and more than 0.5. Hence, these two data set has a strong correlation.
What would the r2 value tell you about the data that you selected?
Ans: The value of r2 is 0.896^2=0.8028. Hence, 80.28% variation of blood pressure is explained by the age.
What is the equation of the regression line?
The regression equation is
Blood pressure = 80.778 + 1.138 Age
Use the regression line to make a prediction about the data you collected.
Age | Blood pressure | Predicted value |
56 | 147 | 144.5060189 |
42 | 125 | 128.5739467 |
72 | 160 | 162.7141015 |
36 | 118 | 121.7459157 |
63 | 149 | 152.472055 |
47 | 128 | 134.2639725 |
55 | 150 | 143.3680138 |
49 | 145 | 136.5399828 |
38 | 115 | 124.0219261 |
42 | 140 | 128.5739467 |
68 | 152 | 158.1620808 |
60 | 155 | 149.0580396 |