A estimates that the mean nitrogen dioxide level in a city is greater than 28 parts per billion . To test this estimate , you determine the nitrogen dioxide levels for 31 randomly selected days . The results in parts per billion ) are listed to the right . Assume that the population standard deviation is 10. At a = 0.12 , can you support the scientist's estimate ? Complete parts ( a ) through ( e ) .

Earth's atmosphere is unique among the planets and is able to support life because it contains a large amount of a) oxygen b) helium c) methane d) carbon dioxide

The smokey mountains have over 2,100 miles of rushing mountain streams and rivers that flow through the park. in each mile lives a diverse community of native fish, amphibians, insects, and larvae, some of which are found only in the southern appalachians. park managers and scientific researchers test many factors such as fish populations, the watersheds and water tests to determine a) too many lizards are present b) the water quality of the stream c) rainwater is running into local streams d) if visitors to the park are overstaying their welcome

What is the most important thing to remember in relation to wild animals?