CF Data Analysis & Reporting 2

Question 1

A forester measures DBH for 50 trees and gets a mean of 18 cm with a standard deviation of 4 cm. What is the coefficient of variation (CV)?

Accepted Answer

22.2%

Answer

CV = (standard deviation / mean) × 100 = (4/18) × 100 = 22.2%.

Question 2

Which sampling design is most appropriate when a forest stand has clearly distinct zones of high-density and low-density trees?

Accepted Answer

Stratified random sampling

Answer

Stratified random sampling divides the population into homogeneous strata, improving precision when distinct zones exist.

Question 3

In a forest inventory report, the term 'basal area per hectare' is expressed in which units?

Accepted Answer

m²/ha

Answer

Basal area per hectare is expressed in m²/ha, representing the cross-sectional area of tree stems at breast height per unit area.

Question 4

A forester uses a relascope with a basal area factor (BAF) of 10. She tallies 14 'in' trees at one point. What is the estimated basal area per hectare?

Accepted Answer

140 m²/ha

Answer

Estimated basal area = number of 'in' trees × BAF = 14 × 10 = 140 m²/ha.

Question 5

Which statistical test is used to compare the means of two independent groups of tree height measurements to determine if they differ significantly?

Accepted Answer

Independent samples t-test

Answer

An independent samples t-test compares means from two unrelated groups to test for statistically significant differences.

(CF) Certified Forester Exam Practice Test

(CF) Certified Forester Exam Practice Test

CF Data Analysis & Reporting 2