The rowan (Sorbus aucuparia) is a tree that grows in a wide range of altitudes. To study how the tree adapts to its varying habitats, researchers collected twigs with attached buds from 12 trees growing at various altitudes in North Angus, Scotland. The buds were brought back to the laboratory and measurements were made of the dark respiration rate. The accompanying table shows the altitude of origin (in meters) of each batch of buds and the dark respiration rate (expressed as µ1 of oxygen per hour per mg dry weight of tissue).
(a) Create a scatterplot of the data.
(b) If your software allows, add a regression line to summarize the trend.
(c) II your software allows, create a scatterplot with a lowess smooth to summarize the trend.