Unit 3: inferential statistics

Question 1

what are the 3 types of sampling?

Answer 1

random sampling
systematic sampling
stratified sampling

Question 2

what is stratified sampling?

Answer 2

ensures that a valid sample is selected for each sub group that you are interested in

Question 3

what is systematic sampling?

Answer 3

occurs when a sampling is selected in a regular manner such as a vegetation sample every 10 meters in a linear direction

Question 4

what is random sampling?

Answer 4

everything has an equal chance of being selected

Question 5

how does a hypothesis testing work?

Answer 5

its a statement or a hunch. to test a hypothesis you write down a statement written as “NH” or “H” and then find evidence to back up statement to prove that there is a change

“NH” - there is no difference
“AH” - there is a difference

Question 6

what is a null hypothesis?

Answer 6

when you do a hypothesis testing bus there has been no change or difference
statements include:
“there is no difference between”
“there has been no change since”
“there is no relationship between”

Question 7

how does a significance testing work/used for?

Answer 7

before you do a test you do a significance test. lets you determine at what point to reject the null hypothesis and accept the alternative hypothesis
Significance is based on probability and chance

Question 8

what is a students t-test?

Answer 8

its used to test the difference between two examples but only for intervals or ratios scale.
the null hypothesis is that the two examples are the same
alt v is that one mean is higher or different to the other

Question 9

One tailed and two tailed tests

Answer 9

with a one tailed test the hypothesis you wish to test (AH) is framed so that the direction is clear
E.G Men are taller than women
or you want to test weather differences exist in any direction - two tailed test
E.G men are a different height to women
–
one tailed - defined statement
two tailed - accepts possibility of a difference