A closer examination of the records of the air samples in Exercise 3 reveals that each line of the data actually represents readings on the same day: 2.92 and 1.84 are from day 1, and so forth. Does...

A closer examination of the records of the air samples in Exercise 3 reveals that each line of the data actually represents readings on the same day: 2.92 and 1.84 are from day 1, and so forth. Does this affect the validity of the results obtained in Exercise 3? If so, reanalyze.

Exercise 3

Table 5.14 shows the observed pollution indexes of air samples in two areas of a city. Test the hypothesis that the mean pollution indexes are the same for the two areas. (Use α = 0:05.)