module 4 - 10.6 representing variation graphically Flashcards
what is discontinuous variation?
- measures certain values
- no in between values
- caused by genetic factors
- presented as bar chart or pie chart
what is continuous variation?
- measurements any values
- continuum of values
- caused by genetic and environmental factors
- caused by genetic and environmental factors
- polygenic and polyallelic
what is a normal distribution curve?
bell shaped curve
what are the features of a normal distribution curve?
- bell shaped - symmetrical about the mean
- mean, mode and median are the same
- half above the mean, half are below
- low values at extremes
what is standard deviation?
quantitative measure of the spread of data about the mean
when would you use students PAIRED t-test?
when measurements come from the same individual/group
when would you use students UNPAIRED t-test?
when measurements come from different individuals/groups
what do you need to do before calculating students t-test?
produce a null hypothesis
what is the null hypothesis?
a prediction that there is no significant difference between the 2 data sets and that any difference is due to chance alone
what is the alternative hypothesis?
a prediction that there is a significant difference between data sets and the difference is not due to chance
what are degrees of freedom?
n1 + n2 - 2
what is x̄1?
mean of first sample
what is x̄2?
mean of second sample
what is s1?
standard deviation of first sample
what is s2?
standard deviation of second sample
