Analyses of drinking water samples for 100 homes in each of two different sections of a city gave the following information on lead levels (in parts per million). Section 1 Section 2 Sample Size 100 100 Mean 34.3 36.1 Standard Deviation 6.0 6.1 (a) Calculate the test statistic and its p-value to test for a difference in the two population means. (Use Section 1 - Section 2. Round your test statistic to two decimal places and your p-value to four decimal places.) z = p-value = Use the p-value to evaluate the statistical significance of the results at the 5% level. H, is rejected. There is insufficient evidence to indicate a difference in the mean lead levels for the two sections of the city. O H, is rejected. There is sufficient evidence to indicate a difference in the mean lead levels for the two sections of the city. O H, is not rejected. There is sufficient evidence to indicate a difference in the mean lead levels for the two sections of the city. O H, is not rejected. There is insufficient evidence to indicate a difference in the mean lead levels for the two sections of the city. (b) Calculate a 95% confidence interval to estimate the difference in the mean lead levels in parts per million for the two sections of the city. (Use Section 1 - Section 2. Round your answers to two decimal places.) parts per million to parts per million (c) Suppose that the city environmental engineers will be concerned only if they detect a difference of more than 5 parts per million in the two sections of the city. Based on your confidence interval in part (b), is the statistical significance in part (a) of practical significance to the city engineers? Explain. O Since all of the probable values of u, - given by the interval are all less than -5, it is likely that the difference will be more than 5 ppm, and hence the statistical significance of the difference is of practical importance to the the engineers. O since all of the probable values of u, - H, given by the interval are all greater than 5, it is likely that the difference will be more than 5 ppm, and hence the statistical significance of the difference is of practical importance to the the engineers. O since all of the probable values of 4 - #2 given by the interval are between -5 and 5, it is not likely that the difference will be more than 5 ppm, and hence the statistical significance of the difference is not of practical importance to the the engineers.