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.
But it is possible to use your sample to calculate a range within which the population value is likely to fall. Likely is usually taken to be 95% of the time, and the range is called the 95% confidence interval. The values at each end of the interval are called the confidence limits. All the values between the confidence limits make up the confidence interval.