The National Oceanic and Atmospheric Administration publishes temperature information of cities around the world in Climates of the World. A random sample of 50 cities gave the data on average high and low temperatures in January shown on the WeissStats CD.
a. Obtain a scatterplot for the data.
b. Decide whether finding a regression line for the data is reasonable. If so, then also do parts (c)–(f).
c. Determine and interpret the regression equation for the data.
d. Identify potential outliers and influential observations.
e. In case a potential outlier is present, remove it and discuss the effect.
f. In case a potential influential observation is present, remove it and discuss the effect.