Concept explainers
Repeat Exercises 1 and 2 for the Year 2 data.
The town of Libby, Montana, has experienced high levels of air pollution in the winter because many of the houses in Libby are heated by wood stoves that produce a lot of pollution. In an attempt to reduce the level of air pollution in Libby, a program was undertaken in which almost every wood stove in the town was replaced with a newer, cleaner-burning model. Measurements of several air pollutants were taken both before and after the stove replacement. They included particulate matter (PM), total carbon (TC), organic carbon (OC) which is carbon bound in organic molecules, and laevoglucose (LE), which is a compound found in charcoal and is thus an indicator of the amount of wood smoke in the atmosphere.
In order to determine how much the pollution levels were reduced, scientists measured the levels of these pollutants for three winters prior to the replacement. The
PM: 27.08 OC: 17.41 TC: 18.87 LE: 2.57
The following table presents values measured on samples of winter days during the two years following replacement.
1. For each of the four pollutants, construct a box plot for the values for Year 1 to verify that the assumptions for constructing a confidence interval are satisfied.
2. Construct a 95% confidence interval for the mean level of each pollutant for Year 1.
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Essential Statistics
- Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt