Statistical techniques

Question 1

What does a low standard deviation show

Answer 1

Low standard deviation shows greater reliability as points are closely grouped to the mean

Question 2

what is standard deviation

Answer 2

a measure of the variation around the mean

Question 3

What is a high standard deviation

Answer 3

data points has a larger range, lower reliability

Question 4

what is this called
(standard deviation)

Answer 4

Confidence limits- determine the range around the mean

Question 5

what is a null hypothesis

Answer 5

this is a statement of what we would expect if there is no significant difference. And if there was to be a difference it is due to chance not correlation

Question 6

what does the x with the line above it stand for

Answer 6

Mean

Question 7

what is a t-test

Answer 7

compare the means of two sets of data to determine whether they are significantly different or not.

Question 8

what test needs to be carried out before a t-test

Answer 8

Standard deviation

Question 9

when do we reject a null hypothesis

Answer 9

when there is a statistically significant difference between the two sets of data.
And when the

Question 10

what is the difference between paired and unpaired

Answer 10

Paired- data between two groups which are the same

Unpaired- data between two different groups

Question 11

when the t test value is higher than the critical value what hypothesis will be accepted.

Answer 11

accept H1 (alternative hypothesis).

Question 12

what is a one tailed test

Answer 12

a test where you know which direction the difference is going in

Question 13

what is a two tailed test

Answer 13

A test where you dont know which direction the difference is going

Question 14

what does significant difference mean

Answer 14

It means there is a factor causing this difference not by chance

Question 15

what does the x-x̄ mean?

Answer 15

X= 1 value of data
x̄=mean

Question 16

what does the n stand for?

Answer 16

n= The total amount of values of data

E.G- In a graph, there is 15 data results, 15-1

Question 17

When finding critical values, what is the probability we always use in Biology

Answer 17

0.05

Question 18

When do we accept H0 and when do we reject H0.

Answer 18

T-test < critical value (Accept H0).

T-test> critical value (reject).

Question 19

how do you work out a degree of freedom for a paired t test

Answer 19

n-1

Question 20

how do you work out a degree of freedom for a unpaired t test

Answer 20

n1-n2-2

Question 21

what is the reason we use the spearmans rank correlation coefficient

Answer 21

Looking if there is a association/ correlation between two sets of data

Question 22

what is the purpose of statistical tests

Answer 22

determine if a relationship is due to chance or an outside factor effecting organisms- effecting the significance of the data