Question

13.7 ls the temperature of the earth getting warmer because heat is trapped by so-called greenhouse gas emissions, such as carbon dioxide, in the earth's atmosphere? The National Climatic Data Center reports on its Web site at http://www.ncdc.noaa.gov/oa/climate/research/anomalies/anom- alies.html that the average global temperatures for recent years have devi- ated above the long-term mean temperature for the entire twentieth century. Expressed in Fahrenheit degrees, the annual deviations above the long-term mean temperature for each of ten recent years, listed in chronological order up to 2007, were 1.0, 0.7, 0.7, 0.9,1.0,1.0,1.0, 1.1, 1.0, and 1.0. (a) Given that X-0.94 and s 0.14 for these ten years, use tat the.01 level of significance to test the nuil hypothesis that the temperature of earth is not getting warmer. In other words, could the sample mean deviation for these ten years have originated from a population of annual deviations for the entire twentieth century having a mean deviation equal to zero? (b) If appropriate (because the null hypothesis has been rejected), construct a 99 percent confidence interval and interpret this interyal,

Answer 1