16.1 A corn farmer is interested in reducing the number of days it takes for his corn to silk. He has decided to set up a controlled experiment that manipulates the nominal variable “fertilizer,” having two categories:

1 = limestone and 2 = nitrogen. Another nominal variable is “soil type,”

with two categories: 1 = silt and 2 = peat. The dependent variable is scale and is the “number of days until the corn begins to silk.” The data are given below; note that they must be entered into Data View in one continuous string of 40 cases. Once the data are entered, you must look for significant differences between the four study groups.
You will also look for any interaction effects between fertilizer and soil and any influence they may have on the number of days to the showing of silk. Write the null and alternative hypotheses, select and conduct the correct test(s), and interpret the results.