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
what is n1?
number of measurements in first sample
what is n2?
number of measurements in second sample
