Download NRM 340 – Exam #1

NRM 340 – Exam #1
Name: _____________
1. I measured the height of a tree one time and got a value of 28
meters. I happen to know the true height of the tree is 30 meters.
Estimate the measurement error.
2. Given the following variables indicate whether they would be nominal,
ordinal, interval, or ratio scale types (N, O, I, R).
(
(
(
(
) Timber types
) Weight of spruce cones
) Finish position in an Olympic event
) Degrees Celcius
3. Length, weight, and area are examples of (continuous, discrete)
variables, while “number of eggs” and “presence or absence of disease”
are examples of (continuous, discrete) variables.
4. Round off the following numbers to the specified significant figures.
Number
4.6495
93.65001
567851
0.99687
4 Sign. Digits
3 Sign. Digits
2 Sign. Digits
5. What phrase best describes the meaning of “the standard error of
the mean”?
a.
b.
c.
d.
the
the
the
the
mean deviation of the measurements
mean of the means
standard deviation of the means
coefficient of determination
6. If the standard deviation of a sample of 36 leaf areas is 4 cm squared
calculate the standard error of the mean.
7. If the mean leaf area in problem #8 was found to be 20 cm squared
what would be the coefficient of variation?
8. You have collected data on weight of forage for a rangeland site and
have found for a sample size of 16 that the mean weight per plot is 24
kg with a coefficient of variation of 50%. Calculate the following:
a. 95% confidence limits =
b. 90% confidence limits =
9. What measurement scale resolution (i.e., smallest unit) should be used
to measure the effect of fertilizer on the growth of barley if the
maximum expected difference between the height of the fertilized
plants and the heights of the unfertilized control plants is estimated
to be 4 cm?
a. cm
b. mm
c. dm (i.e., 1/10 m)
10. The UTM grid system spans strips of ____ degrees of longitude.
These strips are numbered 1 thru _____.
11. Most air photo coverage involves approximately ____ % overlap along
the flight line and approximately ____ % overlap between flight lines.
12. Match the following terms with the correct definition:
a.
b.
c.
d.
e.
population
sample
parameter
accuracy
precision
___
___
___
___
___
the portion of the population that is measured.
indicates the closeness of a measurement to the true value.
the total number of objects in a given area and time period.
a population characteristic.
the degree of agreement in a series of measurements.
13. Given that there are 2.54 cm in an inch convert 4.5 ft to mm.
14. An inventory of a 55-acre white spruce stand was carried out by
taking a random sample of 50 1/5-acre plots. The merchantable cubic
foot volume of sawtimber on each sample plot was determined and the
average volume per sample plot was determined to be 310 cubic feet.
Calculate the estimate of total cubic foot volume of sawtimber for
this stand?
15. Explain the advantages and disadvantages between systematic
sampling, simple random sampling, and stratified random sampling.
16. Suppose we have conducted a preliminary inventory of 25 plots to
estimate volume per acre of a timber stand. From that sample we
estimated the mean to be 4,400 board feet per acre and a standard
deviation of 2,000 board feet per acre. Determine the sampling
intensity needed to be within plus-or-minus 500 board feet per acre,
with a confidence level of 95%.
17. There are _____ townships in a 24 square mile tract and _____
sections within a township. A section is _____ acres.
18. You are told to develop a stratified random sample and allocate a total
of 150 1/10-acre plots. You are given the following information:
h
1
2
3
4
Nh
15
45
110
60
Sh
20
70
35
45
a. Allocate these proportional to strata size.
b. Allocate these optimally to reduce variability within strata.
19. What does magnetic declination tell you?
20. A forester wishes to estimate the proportion of surviving seedlings in
a young plantation. The seedlings were planted at regular spacing and
the forester randomly surveyed 50 seedlings, finding 40 of the
seedlings to be alive. The total number of seedlings planted in the
plantation was 5,000. Calculate a 95% confidence interval.
21. You have a topographic map with a 1:63,360 scale and you want to
know the actual length of a road that measures 2 inches on the map.
What is the actual distance of the road?
22. How far are 3 chains?
23. What is the difference between vertical and oblique air photos?
24. A footpath measures 0.6 inches on an air photo and has an actual
distance of 50 feet. What is the RF of the photo?
25. You have a photo with an RF of 1:10,000 and you measure a bridge in
the photo as 0.48 inches long. What is the actual length of the
bridge?