Niagara Falls is eroding. But the average rate at which it is eroding has changed over time because of human activity. This graph shows the total erosion of Niagara Falls starting in 1900. (The falls were eroding before 1900, but we’ll look only at the changes after 1900 for this study.) Between 1900 and 1905, Niagara Falls eroded an average of 1.16 meters per year. In 1906, around the time the Canadian hydroelectric plant began operating, the erosion rate decreased to approximately 0.7 meters per year.

Part A
Based on the graph, determine how many total meters the falls eroded from 1900 until 1910.

The survey of study habits and attitudes (ssha) is a psychological test that measures the motivation, attitude toward school, and study habits of students, scores range from 0 to 200. the mean score for u. s. college students is about 115, and the standard deviation is about 30. a teacher who suspects that older students have better attitudes toward school gives the ssha to 55 students who are at least 30 years of age. the mean score is 113.2. assume the population standard deviation is 30 for older students what is the margin of error for a 95% confidence interval for the population mean score for a. older students? b. compute the 95% confidence interval for the population mean score for older students. c. compute the 99% confidence interval for the population mean score for older students. d. compute the 88% confidence interval for the population mean score for older students.