27. Acidity in Rainfall Refer to Exercise 30 (Section 8.3)

and the collection of water samples to estimate the mean acidity (in pH) of rainfalls. Remember that the pH for pure rain falling through clean air is approximately 5.7.

The sample of n540 rainfalls produced pH readings with x 53.7 and s5.5. Do the data provide sufficient evidence to indicate that the mean pH for rainfalls is more acidic (H :m , 5.7 pH) a than pure rainwater? Test using a 5.05. Note that this inference is appropriate only for the area in which the rainwater specimens were collected.