The anticipation of the first blooms of spring flowers is one of the joys of April. One of the most beautiful is that of the Japanese cherry tree. Experience has taught us that, if the spring has been a warm one, the trees will bloom early, but if the spring has been cool, then the blossoms will appear later. Mr. Yamada is a gardener who has observed the date in April when the blossoms first appear for the last 24 years. His son, Hiro, went on the internet and found the average March temperature (in degrees Celsius) in his area for those years. For example, for the first year in the data table, the average March temperature was 4°C and the first bloom happened on the 14th day of April.
1. Why should temperature be the explanatory variable?
