- Hp 300 250 200 150 100 Co Ecc 3 3 2 32 Model 1973 1974 Cars Hp Vs Gear Motor Trend Us Magazine 4 2 4 4 3 4 3 6 3 1 (51.85 KiB) Viewed 31 times
Quarter of Mile Time [Seconds] 22 21 20 19- 18- 17- 16- 15- 32 Model 1973-1974 Cars: Q. Sec. vs. # of Cylinders (Motor Trend US magazine) T 4 4.5 5 5.5 6 6.5 Number of Cylindars Use the graphs to answer the following questions. T 7 T 7.5 ***** CO 8
Question 1 3 pts MTCARS Assume that the 32 cars in mtcars dataset is a representative sample of all 1973-74 models. Select the correct populations and hypotheses associated with the use of ANOVA on horsepower vs gear graph. Population ✓ [Choose ] HO: the mean hp for all numbers of gears are the same Ha: The mean hp is different for all number of gears. determine by values of gear, {3, 4, 5} The NULL Hypothesis HO: hp for all number of gears are the same The Alternative Hypothesis Ha: The mean hp is different at least for one number of gears. determine by values of gear, a real number between 3 and 5 determined by values of hp, a real number between 50 to 400. Question 2 3 pts
Question 2 3 pts MTCARS ANOVA assumptions include: 1. normality of observations in each group and 2. equality of variance. Consider the Acceleration vs Cylinders graph. Select all correct statements regarding ANOVA assumptions. The ANOVA assumptions are most likely met. The variance of Acceleration seems to be equal between cars with different number of cylinders.. ✔There is a clear outlier in on of Cylinder groups. Number of observations in each group is less than 30.
[ ANOVA With Numerical Group Variable When the populations in ANOVA are determined by a numerical variable, ANOVA data can be treated as Regression data: • Equality of means in ANOVA is equivalent to a horizonal line y = bo be the best fit. • If the relation is linear, then having different means in ANOVA is equivalent to having a line y = bo + b₁ x with a non-zero slope. Consider the following two graphs:
ан 300 250 200 150 100 3 3.2 32 Model 1973-1974 Cars: HP vs Gear (Motor Trend US magazine) 4 4.2 4.4 4.6 Gear 3.4 3.6 3.8 4.8 5
Quarter of Mile Time [Seconds] 22 21 20 19 18 17 16 15 ● 32 Model 1973-1974 Cars: Q. Sec. vs. # of Cylinders (Motor Trend US magazine) 4 4.5 5 5.5 6 6.5 Number of Cylindars Use the graphs to answer the following questions. 7 7.5 30 OC CO 8
Question 3 MTCARS: Linear Regression Match the descriptions to graphs: HP vs Gears Acceleration vs Cylinders 2 pts [Choose ] Linear, Positive, Strong Non-linear, Negative, Strong Linear, Negative, Moderate Non-linear, Negative then Positive; Moderate, strong, then weak 20
MTCARS: Linear Regression The following tables shows the summary statistics for each graph: 32 Cars, cor(gear, hp)=-0.126 Variables Mean SD gear 3.688 0.738 hp 146.688 68.563 32 Cars, cor(cyl, qsec)=-0.591 Variable Mean SD cyl 6.188 1.786 qsec 17.849 1.787 For the graph that a linear relation exists, find the slope and intercept. Bring this to class to share with your group and use to answer other questions.