processing and presenting data Flashcards
outline a students t-test
it tests for a significant different in the means of two data sets
t-test value would be greater than p value if the difference is significant
- identify the null hypothesis
- calculate the mean and standard deviation for each data set
- use formula given
- calculate the degrees of freedom using (n1+n2)-2
- reject the null hypothesis if t-test value is above the critical value
outline a chi-squared test
used with categorical data when you are comparing wether observed results are statistically different from expected results
equation is given
if the chi-squared value is higher than or equal to the p value, the difference is significant
outline a correlation coefficient
eg. pearson’s correlation coefficient (r)
it allows you to work out the degree of correlation between two sets of continuous data
value will between 1and -1
how do you use this equation to calculate standard deviation
what environmental factors can cause cancer
diet, weight, alcohol, age
when is a students t-test used
to determine whether two sets of data have significantly different means
what is important to mention when name dropping respiration
aerobic/anaerobic
ALWAYS SAY!!!
what should u put in 6 markers always?
repeat and find the mean
do a stats test! students t-test looks for sig. difference between two means
what do you need to include in a 9 marker that says evaluate with an asterisk
a conclusion!!! make a decision
what can you do if you’re given at least one piece of data in a 6 marker
evaluate it
validity etc.
how do you calculate the degrees of freedom for students t-test
n1 + n2 - 2
how do you calculate the degrees of freedom for spearman’s rank
just n
how do you calculate the degrees of freedom for chi2
n-1
when doing standard deviation do you include values that had 0 when doing x-mean in your total no. values
yes still include them in n-1
how do you write a null hypothesis
there is no correlation between x and y
