Section 4 Measurements (in cm) of diameter at breast height (dbh) were taken of 15 trees in a Douglas-fir stand: 17.2 18.9 16.2 25.8 24.5 25.1 27.8 29.2 16.1 18.4 25.7 23.2 30.1 17.2 27.9 Answer the following questions (Part 1 to Part 15) using this description.Part 1 To find the 90% confidence interval for the mean of all tree diameters in this stand, which probability distribution should be used? O Chi-squared distribution O F distribution O Z distribution O t distribution Question 14 1 pts Part 2 What is the standard error of the mean of all tree diameters in this stand?Part 3 To calculate the 90% confidence interval for the mean of all tree diameters of this stand, what tabulated value should be used? For example, for finding a 95% CI for the Z distribution, 1.96 should be used (see figure 6.1 in Lesson 6 and Table A.4 in the textbook). For finding a 95% CI for the t distribution with 10 df, we use 2.23 (see Table A.5 in the Appendix in the textbook). These are not the answer, but are meant to give you an example of what this tabulated value looks like. Hint: Use two decimals, and enter the exact value you find in the appropriate table in the textbook Appendix. Enter the value exactly as it is written. Question 16 0.5 pts Part 4 Find the 90% confidence interval for the mean of all tree diameters in this stand. What is the lower limit?Part 5 Find the 90% confidence interval for the mean of all tree diameters of this stand. What is the upper limit? Question 18 1 pts Part 6 To calculate the 95% confidence interval for the mean of all tree diameters in this stand, what tabulated value should be used? For example, to find a 95% CI for the Z distribution, 1.96 should be used (see figure 6.1 in Lesson 6 and Table A.4 in the textbook). To find a 95% CI for the t distribution with 10 df, 2.23 is used (see Table A.5 in the textbook). These are not the answer, but are meant to give you an example of what this tabulated value looks like. Hint: Use two decimals, and enter the exact value you find in the appropriate table in the Appendix. Enter the value exactly as it is written.Part 7 Find the 95% confidence interval for the mean of all tree diameters of this stand. What is the lower limit