lesson 3 Flashcards
whatre R groups
-need to mention groups when talking about tertiary structure
-determines interactions that happen to give protein tertiary shape
-what makes each amino acid unique
what does students T-test measure
used to compare the means of 2 sets of data and decide if they’re statistically significantly different
whatre the first steps of student T test (until squared standard deviations/number observations)
1)calculate mean for each data set
2)calculate the standard deviation for each dataset (s1 for standard deviation of sample 1 and s2 for standard deviation of sample 2)
3)square the standard deviations and divide by the number of observations in each sample (n1 and n2)
What does the last step look like in the equation
s²1 s²2
—– —–
n1 n2
Describe the next steps of student t test
4) add the products of step 3 together and find the square root
5)subtract the mean of sample 2 from the mean of sample 1 then divide this by the product of step 4
What value do we get from step 5
The T value
what do we need to compare the T value to?
find degrees of freedom of both samplesook at a table of t values and find which t value the degree of freedom calculated lies
how do you calculate degrees of freedom (equation wont be provided)
number of individual measurements in a sample -1 (n1-1 + n2-1) =V
part of equation for the difference between 2 means
_ _
X1 - X2
whole equation (will be provided)
__ __
t= X1 - X2
——————-
√ s ²1 + s ²2
( —- —- )
n1 n2
calc mean of each dataset & subtract sample 2 from sample 1
find standard deviations for each dataset
square standard deviations of each dataset
divide by the number of individual measurements in each sample (separately form samples 1 and 2)
add these together then square root
divide difference of means by square root
thats the t value
find degrees of freedom, V (number if measurements in one sample-1, n1-1+n2-1)
see which value the degree of freedom relates to on a table comparing t values to degrees of freedom - critical valuesat right significance level (usually 5%)
t value>critical value means difference is likely signifdif and not due to chance- null hypothesis rejected
t value<critical value any difference is likely due to chance and not signif
The probability that any difference is due to chance is higher than 5 %
The null hypothesis is accepted