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C11 (30 points) Corporate sustainability refers to business practices designed around social and environmental considerations. Refer to the Business and Society (March 2011) study on the sustainability behaviors of CPA corporations. The level of support for corporate sustainability (measured on a quantitative scale ranging from 0 to 160 points) was obtained for each in a sample of 992 senior managers at CPA firms. Higher point values indicate a higher level of support for sustainability. The sample mean is 67.755 and sample standard deviation is 26.871 a. calculate the 90% confidence interval for population mean b. calculate the 95% confidence interval for population mean c. calculate the 98% confidence interval for population mean