statistics

T- Test - used to test if

the difference between the two means is significant

t test - null hypothesis

there is no significant difference between the means of…

T test - degrees of freedom

number of values in first data set -1

+

number of values in second data set -1

T test - test value

larger the T value = bigger the difference between the means

T test - conclusion

if T value > critical value, probability of difference between the means being due to chance <5%

reject null hypothesis, difference is significant

Chi squared test - used to test if…

the difference between observed and expected frequencies is significant

chi squared test - null hypothesis

there is no significant difference between the observed and expected frequencies of …

chi - squared test - degrees of freedom

number of categories - 1

chi squared test - test value

larger the X*2 value = bigger difference between observed and expected frequencies

chi squared test - conclusion

if X*2 value> critical value, probability of difference between observed and expected frequencies being due to chance <5%

reject null hypothesis, difference is significant

Spearmens rank - correlation coefficient - used to test if…

the corelletion between two sets of data is significant

SR - null hypothesis

there is no significant correlation between…

SR degrees of freedom

number of paired measurements - 1

SR test value

0= no correlation

-1 = perfect negative correlation

+1 = perfect positive correlation

SR - conclusion

if rs value > critical value probability of correlation being due to chance <5% reject null hypothesis, correlation is significant