A scientist estimates that the mean nitrogen dioxide level in Calgary is greater than 32 parts per billion. You want to test this estimate. To do so, you determine the nitrogen dioxide levels for 34 randomly selected days. The results (in parts per billion) are shown in the table. Assume the population standard deviation is 9 parts per billion. At α = 0.06, can you support the scientists estimate?

(a) Identify the claim and state H₀ and H_a,

(b) Find the critical value(s) and identify the rejection region(s),

(c) Find the standardized test statistic z,

(d) Decide whether to reject or fail to reject the null hypothesis,

(e) Interpret the decision in the context of the original claim. If convenient, use technology.

Nitrogen dioxide levels (in parts per billion) 24 36 44 35 44 34 29 40 39 43 41 32 33 29 29 43 25 39 25 42 29 22 22 25 14 15 14 29 25 27 22 24 18 17