1 Recycling one ton of newspaper saves 15 trees. 2  Every ton of newspaper recycled saves 4100 kWh or enough energy to power a TV for 31 hours. 3  Recycling a soda can saves 96 percent of the energy used to make a can from ore and produces 95 percent less air pollution and 97 percent less water pollution. Recycling one ton of cardboard saves over nine cubic yards of landfill space. 2  Number of landfills in operation in 1978: 14,000; in 1988: 7,924; in 2001: 1,858; in 2006: 1,754. 3  Recycling one ton of newspaper saves 15 trees. 4  Every ton of newspaper recycled saves 4100 kWh or enough energy to power a TV for 31 hours.
Once the standard error is calculated, the confidence interval is determined by multiplying the standard error by a constant that reflects the level of significance desired, based on the normal distribution. The constant for 95 percent confidence intervals is 1.96.
The correct answer is (A). To specify the confidence interval, we work through the four steps below. Identify a sample statistic. Since we are trying to estimate the mean weight in the population, we choose the mean weight in our sample (180) as the sample statistic.