Assume that for the city of Hamilton, Ontario, an environmental study reported that the

average number of micrograms of suspended particles per cubic metre of air is 82. Suppose Hamilton

officials have been working with businesses, commuters, and industries to reduce this figure. These

city officials hire an environmental company to take random measures of air soot over a period of

several weeks. The resulting data are shown below. Assume that the population standard deviation is

8.194. Use these data to determine whether the urban air soot in Hamilton is significantly lower than

what the environmental study reported. Let = 0.01. If the null hypothesis is rejected, discuss the

substantive hypothesis. Use Z.TEST dialog box.