FOR 274 Assignment 2 [50 points] Name: Section:

Transcription

1 value FOR 274 Assignment 2 [50 points] Name: Section: This assignment should be completed and handed in to the assignment box in the Forest Resources office by noon on Monday 10th of September. Partial credit will only be given for incorrect answers if you show your work. 1. What is wrong with the following figures: a. b consumption of wine has doubled in two years USA 2. What type of data are represented by the following: a. Temperature of the water in a river? b. Velocity of flow in the river channel? c. Type of car in a survey on commuting habits? d. Satisfaction rating (very good, good, indifferent, bad, very bad) in a survey of attitudes towards rail travel since privatization? 3. What is the quadratic mean diameter of the following set of tree diameter measures? , 12.6, 16.9, 18.5, 14.2, Calcualte to the nearest 1/10 th foot the radius of a 5 th, 10 th, and 100 th acre circular plot.

2 5. Calcualte to the nearest 1/10th meter the radius of a 7 th, 12 th, and 30 th hectare circular plot. 6. Calcualte to the nearest 1/10 th foot the length of the side of a 5 th, 10 th, and 100 th acre square plot. 7. Calcualte to the nearest 1/10th meter the length of the side of a 7 th, 12 th, and 30 th hectare square plot. 6. Consider the following data: Tree # DBH (in) Tree # DBH (in) a. Estimate the mean DBH. b. Estimate the standard error of the mean. c. Compute the 95% confidence limit of the mean d. Is the distribution skewed? If so, is it positive or negative?

3 7. A Broader Perspective The following table represents the mean life expectancy at birth by gender for different countries in Africa since 1995 (data from the UN at Male Female Male Female Male Female Algeria Gambia Niger Botswana Ghana Nigeria Burkina Faso Guinea Rwanda Burundi Guinea-Bissau Senegal Cameroon Kenya Sierra Leone Central African Republic Lesotho Somalia Chad Liberia South Africa Congo Libyan Arab Jamahiriya Sudan Côte d'ivoire Malawi Swaziland Dem. Republic of the Congo Mali Tunisia Egypt Mauritania Uganda Eritrea Morocco United Rep. Of Tanzania Ethiopia Mozambique Zambia Gabon Namibia Zimbabwe (For comparison, the current figures for the USA are 75.6and 80.8 years). a. Calculate the central tendency of these data using both the mean and median for both males and females. Why are these values different? b. Calculate the range, interquartile range and standard deviation of these data. c. Why do these summary measures NOT represent the average life expectancies for individual males and females in Africa as a whole? What other piece of information would you need to make this calculation? d. Using any graphical method, describe the distribution of these data. e. Is there any clumping of the data values? f. Are there any outliers? If so, what country or countries do they represent and why do you think this is so? g. How might you explore the relationship between the male and female longevity in the different countries of Africa?

4 8. Assuming that each of your paces is 3 ½ feet, calculate the following horizontal distances to the nearest foot: a. A flat distance between A and B of 32 paces? b. A flat distance between A and B of 27 paces? c. The horizontal distance between A and B when the distance on a slope of 30 is 11 paces? d. The horizontal distance between A and B when the distance on a slope of 60 is 39 paces? 9. Calculate the total height, crown base height, and crown length for the depicted tree: +95% +10% 90 feet horizontal distance 10. With your measurements from question #9 and knowing that the major and minor access of the tree are 21.5 and 18.6 feet respectfully, calculate the crown volume and surface area. -12%

5 11. Refer to the following figures to complete the following tables: A B C A C B a b c A B C A c b C a B 12. What should be the sum of the interior angles for closed traverses having: a. 3 sides b. 8 sides c. 12 sides Challenge Problem You are told to reasses two old inventory plots, the first is 6 chains at N46 E from your truck and then you continue on along a ridge at S115 E for 5 chains. What is the distance and direction you must travel in order to return to your starting location?