Processing and presenting data

Question 1

percentage change

Answer 1

(final value - original) x 100 / original value

Question 2

range

Answer 2

substract smallest value from largest

Question 3

why is SD used over range

Answer 3

how value are spread from the mean rather than total spread

Question 4

what does a small SD show

Answer 4

small spread from mean

Question 5

t test

Answer 5

• 2 sets of data to compare
• whether there is a significant difference in the means of the two data sets
• compared to a critical value
  
  • how liekly the difference in the means were due to chance
• if value obtaining is <0.05, 95% confidence that the difference is significant, and not due to chance
• reject null hypothesis

Question 6

null hypothesis

Answer 6

states there’s no significant difference between the things you’re measuring

Question 7

chi-squared test

Answer 7

• used when you have catergorical data you want to compare whether youe observed results are statistically different from your expected results
• compare to critical value
• if larger than P=0.05, you can be 95% certain the differnece is significant

Question 8

present qualatative data or discrete data

Answer 8

bar chart or pie chart

Question 9

present continuous data

Answer 9

histogram or line graphs

Question 10

present one varaible against another

Answer 10

scatter graph

Question 11

find gradient of curved section of graph

Answer 11

use tangent