Worksheet1-1

MATH 201 Statistics for Environmental Professionals ● Worksheet 1 Name Section 1. Suppose that you are a wildlife biologist working in a National Park. One of your tasks is to conduct demographic surveys of American alligators in the park. You have conducted a nightlight survey and measured encountered alligators. The survey data are shown in the below table. Answer the following questions using this dataset. Animal ID Habitat type Water temperature (°C) Head Length (cm) Total Length (cm) Weight (kg) Sex Number of deformities 1 Marsh 20 21.2 144.5 9 Female 0 2 Marsh 19 25.6 185.2 16 Male 0 3 Marsh 20 20.4 139.9 8 Female 0 4 Marsh 19 26.8 203.3 19 Female 1 5 Marsh 20 30.0 211.5 17 Male 0 6 Marsh 22 30.0 224.5 28 Female 1 7 Marsh 20 29.5 212.8 17 Male 0 8 Marsh 20 26.9 195.8 19 Male 0 9 River 23 25.7 186.9 19 Male 0 10 River 23 32.9 247.7 39 Male 0 11 River 23 29.6 210 27 Female 0 12 River 25 24.3 178.5 15 Male 2 Question 1. How many variables are in the data set? Refer to the textbook 1.1. (5 pts.) 8 Question 2. List all numerical (quantitative) variables and classify them into continuous or discrete. Refer to your textbook 1.1 & 1.2. (5 pts.) Discrete- number of deformities, animal ID Continuous - Temperature, head length, total length, weight, Question 3. Find the median weight of the female alligators. Show your work. Refer to the textbook 2.3. (10 pts.) 8 9 19 27 28 = 19 Question 4. Calculate the mean weight of the female alligators.. Show your work. Refer to the textbook 2.5. (10 pts.)

9+8+19+28+27= 91/5= 18.2 Question 5. Find the standard deviation of weight of the female alligators.. Show your work. Refer to the textbook 2.7. (10 pts.) 1. Find the mean: Mean=9+8+19+28+275=915=18.2 2. Subtract the mean from each data point and square the result: (9−18.2)2=82.44(9−18.2)2=82.44 (8−18.2)2=105.64(8−18.2)2=105.64 (19−18.2)2=0.64(19−18.2)2=0.64 (28−18.2)2=96.04(28−18.2)2=96.04 (27−18.2)2=76.84(27−18.2)2=76.84 3. Find the mean of these squared differences: Mean of squared differences=82.44+105.64+0.64+96.04+76.845=361.65=72.32 4. Take the square root of that mean: Standard Deviation=72.32≈8.50 Question 6. Using the descriptive statistics Excel worksheet provided, calculate the descriptive statistics for one of the following variables: head length, total length, or weight. (10 pts.) Chosen Variable weight Sample size (n) Mean Standard deviation Minimum 1st Quartile Median (2nd Quartile) 3rd Quartile Maximum (4th Quartile) 12 (?) 21.08 8.45 8 15 18 23 23 Section 2. Suppose that you are an employee of the United Nations Environment Programme for forest conservation. You are assigned to summarize the recent deforestation rate by country using a graph and interpreting the graph. The accompanying file contains a part of the data of nationwide deforestation rate (percentage) in 2020. Answer the following questions using the dataset. Question 1. Using Excel, create a histogram of percentage of deforestation with bin width (width of each bar) 5. Attach the histogram to this report. (20 pts.)