No explanations needed, only the correct solutions, thank you:

1.

The grade point averages (GPA) for 12 randomly selected college students are shown on the right. Complete parts (a) through (c) below. 2.3 1.1 2.5 E 1.7 0.9 4.0 Assume the population is normally distributed. 2.4 1.3 3.6 0.3 2.5 3.4 (a) Find the sample mean. (Round to two decimal places as needed.) (b) Find the sample standard deviation. (Round to two decimal places as needed.) (c) Construct a 90% confidence interval for the population mean u. A 90% confidence interval for the population mean is (Round to two decimal places as needed.)Use the value of the linear correlation coefficient to calculate the coefficient of determination. What does this tell you about the explained variation of the data about the regression line? About the unexplained variation? = 0.103 Calculate the coefficient of determination. (Round to three decimal places as needed.) What does this tell you about the explained variation of the data about the regression line? % of the variation can be explained by the regression line. (Round to one decimal place as needed.) About the unexplained variation? % of the variation is unexplained and is due to other factors or to sampling error. (Round to one decimal place as needed.)