biology maths skills Flashcards
how do you go from nano to micro metres?
/1000
how do you go from micro to nano metres?
x 1000
how do you go from micro to milli metres?
/1000
how do you go from milli to micro metres?
x 1000
what is the mean?
total/ how many values
what is the mode?
most common
what is the median?
middle value
what is standard form?
a x 10^n
what are logs used for?
converting large numbers onto a small scale
when do you use a Chi Square test?
when looking at the number of individuals in a category
when do you use a Student’s T Test?
when looking at the difference between mean values
when do you use a Spearman’s rank correlation?
when looking at the association between measurements from the same sample
what is the null hypotheses?
when there is no significant difference between variables
when do you reject the null hypotheses?
when the data is significant, test statistic>critical value
what happens when the the probability is above 5%?
generally due to fluke/chance
what are the degrees of freedom for Chi Square?
categories-1
what are the degrees of freedom for T Test?
repeats -2
what are the degrees of freedom for correlation co efficient?
n= number of pairs investigated
what does standard deviation show?
how spread out measurements are from the mean
what does it mean if standard deviation bars overlap?
no significant difference between the two bars- any difference is due to chance
how do you work out percentage increase?
(difference/original value) x 100
