The Environmental Protection Agency
releases figures on urban air soot in selected cities in the United
States. For the city of St Louis, the EPA claims that the average
number of micrograms suspended particles per cubic meter of air is
82. Suppose St Louis officials have been working with business,
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 follow.
Use these data to determine whether the urban air soot in St Louis
is significantly lower than it was when the EPA conducted its
measurements, assuming you want to take only 3% risk of committing
a Type I error.
|
81.6 |
66.6 |
70.9 |
82.5 |
58.3 |
71.6 |
72.4 |
96.6 |
78.6 |
76.1 |
80 |
73.2 |
85.5 |
73.2 |
68.6 |
74 |
|
68.7 |
83 |
86.9 |
94.9 |
75.6 |
77.3 |
86.6 |
71.7 |
88.5 |
87 |
72.5 |
83 |
85.8 |
74.9 |
61.7 |
92.2 |
A. POPULATION
*Determine the population type
*State H0 and Ha ( in words and using m or
p)
*Describe a Type I error and a Type II error IN CONTEXT
B. STATISTICAL METHOD
*How much confidence is desired? Determine α
*Write the formula of the test statistic (using the hypothesized
value from H0)
*Write the formula for the confidence interval.
*Choose and write your decision criteria (critical value ,
p-value, or both)
C. SAMPLE
*Describe the sample and check that the sample meets the
necessary assumptions.
D. STATISTICAL RESULTS
*Compute the value of the test statistic
*Compute the p-value, the critical value or both (based on your
decision criteria in B)
*Construct the confidence interval for your population
characteristic
E. CONCLUSION
*Make a concluding statement based on your decision criteria and
your confidence interval
