investigation variation/ diversity

Question 1

what is standard deviation

Answer 1

a measure of the spread of the values about the mean

Question 2

what does a large standard deviation mean

Answer 2

means the values in the sample vary a lot

Question 3

what does a small standard deviation mean

Answer 3

most of the sample data is around thee mean value

Question 4

where is the mean in error bar

Answer 4

in the middle

Question 5

what does a long bar tell us

Answer 5

a larger standard deviation

Question 6

what is the advantage of using standard deviaiton instead of a range

Answer 6

• SD shows the spread of data around the mean, whilst the range shows the difference between the highest and lowest value.
• SD reduces affects of anomalies whilst range includes anomalies
• SD can be used to identify wether

Question 7

what does overlapping data show

Answer 7

theres no significant difference

Question 8

what does non-overlapping data show

Answer 8

the data is significantly different

Question 9

what is the depemdant variable

Answer 9

variable we measure

Question 10

where does the independant variable go on a graph

Answer 10

x axis

Question 11

where does the dependant variable go on a graph

Answer 11

on the y axis

Question 12

what does a positive r value indicate

Answer 12

positive correlation

Question 13

when can you use the correlation coefficient

Answer 13

looking to find the strength between thee dependant and independant variable

Question 14

what is the purpose of a student t test

Answer 14

investigates the difference between two means

Question 15

what is a paired t test

Answer 15

when both groups have the same sample size

Question 16

what are the limitations of a student t-test

Answer 16

only used to compare 2 independant data sets
only appropriate when theres no outliers or skew

Question 17

what is a null hypothesis

Answer 17

theres no relationship between the variables

Question 18

what does a p value greater than 0.05 suggest

Answer 18

results are due to chance

Question 19

what happens to the null hypothesis if p is above the critical value

Answer 19

we accept the null hypothesis

Question 20

if the p value is less than 0.05 what happens to the null hypothesis

Answer 20

we reject the null hypothesis

Question 21

what does a chi-squared test measure

Answer 21

it measures the difference between the observed and expected value

Question 22

when chi squared is greater than 0 what does this tell us

Answer 22

theres some difference between the observed and expected results

Question 22

what cant chi squared tests take

Answer 22

negative values