1. An experiment is carried out to determine the relationship between the average speed (rpm) and power (hp) of a mixer. Construct a scatter plot for the data obtained in the experiment.
Run Average Speed x, Power y,
1 325.0 1.10
2 348.9 1.40
3 312.9 1.07
4 230.0 0.25
5 269.2 0.64
6 305.0 0.93
2. A realtor wanted to determine if there was a relationship between the size (in 100 square feet) of a new custom-built home and the price (in thousands of dollars) of the home. Find the equation of the regression line and graph the line on a scatter plot.
Size, Price,
26 235
27 273
41 387
29 253
33 295
34 335
36 395
45 475
22 203
3. A study was conducted to determine if there was a linear relationship between a person's age and his/her peak heart rate. Construct a scatter plot and determine what type of relationship there is between a person's age and his/her peak heart rate.
Age x, Peak Heart Rate y,
16 220
26 194
32 193
37 178
42 172
53 160
48 174
21 214
4. Draw a scatter plot for the following data that show the demand for a product (in hundreds) and its price (in dollars) charged in nine different cities.
City Price x, Demand y,
1 23 17
2 18 48
3 19 41
4 21 38
5 20 33
6 25 17
7 22 35
8 17 52
9 22 24
5. A psychologist wants to determine if there is a linear relationship between the number of hours a person goes without sleep and the number of mistakes he/she makes on a simple test. The following data is recorded. Determine the equation of the regression line and graph the line on a scatter plot.
Hours without Sleep x, Number of Mistakes y,
32 6
38 8
48 13
24 5
46 7
35 6
30 5
34 8
42 12
6. Compute the slope of the regression line for the data below.
X values –3 1 3 7 8
Y values 5 5 –3 4 –2
7. Compute the slope of the regression line for the data below.
X values –4 –1 5
Y values 4 5 –3
8. Compute the standard error of the estimate for the data below.
X values –4 0 5
Y values 3 3 –2
9. Compute the intercept of the regression line for the data below.
X values –4 0 2 9
Y values 4 5 –1 0