University:
High School
Course:
High School Biology
Academic year:

2022
Views:

409

Pages:

1
Author:

anon

Biology Unit One – Statistics ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● Normal distribution – bell shaped curve with the peak in the center Calculating the mean of a set of values involves dividing the sum of all the values by the total number of values. Standard deviation – used to assess how far the values are spread above and below the mean 68% of all values fall between ± 1 standard deviation 95% of all values fall between ± 2 standard deviation Can be positively or negatively skewed Lower standard deviation means a lower range of values Null hypothesis – there is no significant difference between the two sets of data T-test can be used to find out whether there is a significant difference between the two sets of data Degrees of freedom – total population minus 2 If the calculated value of t is lower than the critical value then there is no significant difference between the two values and the null hypothesis can be accepted If the calculated value of t is higher than the critical value then there is a significant difference between the two values and the null hypothesis can be rejected Level of significance chosen should be 5% (showing that the probability of random variation is 5% or less) If there is a correlation between to the two variables it does not always signify a cause and effect relationship Requires further study in order to prove the relationship