Math

Question 0

95% confidence level

Answer 0

1.96

Question 1

90% confidence level

Answer 1

1.64

Question 2

99% confidence level

Answer 2

2.57

Question 3

Hypothesis testing

Answer 3

Confidence intervals give us a region that may contain the true population parameter.
It is a process of testing whether the CI contains a specific value

Question 4

Simple random

Answer 4

Every individual has an equal chance of being selected

Question 5

Advantages and disadvantages to random sampling

Answer 5

Advantages: truly unbiased
Disadvantages:geography,a chance u have no variety

Question 6

Systematic sampling

Answer 6

Pick random location and sampling interval

Works well with tree plantations

Question 7

Advantages and disadvantages of systematic sampling

Answer 7

Advantages: efficiency, uniform coverage
Disadvantages: not “truly” unbiased,pattern in the landscape makes a problem

Question 8

Stratified random sampling

Answer 8

Obvious groups in your sample that could influence your population mean, most be aware of groups before hand

Question 9

Stratified sampling advantages and disadvantages

Answer 9

Advantages: know differences between groups
Disadvantages: more complex, assumes u know proportions so needs additional math

Question 10

Cluster sampling

Answer 10

Sampling groups of like individuals to estimate some measurements of those individuals

Question 11

Advantages and disadvantages of cluster sampling

Answer 11

Ad: efficient, scattered objects across space
Dis: potential for pseudoreplication (outliers)

Question 12

Difference between stratified sampling and cluster sampling

Answer 12

Stratified: smaller variance within stratum than across strata ( you want variation!)
Cluster:larger variance within a cluster than across clusters (more similar than different)

Question 13

Basal area measurements

Answer 13

Basal area (ft2)= dbh2x 0.005454 where dbh is measured in inches
Basal area(m2) = dbh2x0.0000785398 where dbh is measured in cm

Question 14

Clinometer

Answer 14

Measures height math % to ground +% to the top

Question 15

Prism

Answer 15

Point sampling

Question 16

What is a sample?

Answer 16

Representative piece of pie

Question 17

Why take a sample?

Answer 17

Ad: quicker, easier ,cheaper
Dis: depending on sample size it’s inaccurate

Question 18

Universe

Answer 18

Total # of objects of interest

Question 19

Population

Answer 19

The attributes of interest on all N objects in the universe

Question 20

Statistic

Answer 20

An estimator of a specific parameter calculated from the sample of the population

Question 21

Parameter

Answer 21

A collective property of the population

Question 22

Quantitative

Answer 22

Quantity and numbers

Question 23

Qualitative

Answer 23

Words descriptions

Question 24

Continuous

Answer 24

Decimal points,mean something

Question 25

Discrete

Answer 25

Whole numbers

Question 26

Interval

Answer 26

No “ natural zero” different meaning than nothing

Question 27

Ratio

Answer 27

Some relationship between 2 numbers

Question 28

Proportions/percentages

Answer 28

Fractions

Question 29

Mean advantages and disadvantages

Answer 29

Ad: useful for stats
Dis: biased by outliers

Question 30

Median advantages

Answer 30

Better description of outliers

Question 31

Mode advantages and disadvantages

Answer 31

Ad: useful for descrete data
Dis: not so useful for continuous data