Midterm - Hypothesis Testing Flashcards
mu for student’s t distribution equation for averages
1.1
mu for student’s t distrubtion equation for single measurement
1.2
difference between t test mu for single and average measurements
for averages, divide s by sqrt(n), for single don’t need to do this step
What is the procedure for a Q test?
arrange the data in increasing order: x1, x2, x3, _ xn, the value in question will either be x1 or xn
How to calculate Q?
Q=distance to nearest neighbor/full range of values
how to conclude Q test:
if Qcalc > Qtable, then reject value
What is Q test for?
Decide if you can reject outlier
What is N on Q table?
number of data points
what value do you calculate to compare an average of several results to an ‘expected’ value?
tcalc, mu
what is the equation for tcalc?
1.3
what is the equation for mu when you’re calculating tcalc?
1.4
how to conclude t test to compare an average of several results to an ‘expected’ value?
if tcalc > t table, then xbar is significantly different than mu
What is comparing two averages, xbar1 and xbar 2 test used for?
are the differences between the averages of two sets of measurements (N1 and N2) significant or do they reflect samples of the same distribution?
What do you calculate for comparing two averages xbar1 and xbar2 test?
tcalc and sp^2
what is the equation for tcalc for comparing two averages xbar1 and xbar2?
GIVEN
What is the equation for sp for comparing two averages xbar1 and xbar2?
GIVEN, BUT don’t forget it gives sp^2 so you need to square root answer
How to conclude test for comparing two averages, xbar1 and xbar2?
if tcalc > t table, then the two averages are significantly different
what are the DOF for comparing two averages, xbar1 and xbar2?
DOF=N1+N2-2
What does the Fishers F test test for?
comparing two sample variances, s1^2 and s2^2
What is the Fishcers F test asking?
are the differences between sample variances from two sets of measurements (N1 and N2) significant or do they reflect samples of the same distribution? (same population variances)?
How to calculate Fcalc:
Sl^2/Ss^2 where Sl^2 and Ss^2 are the larger and smaller variances so F>1
How to conclude F test:
if Fcalc > Ftable, the Sl^2 is significantly greater than Ss^2
What are the DOF for the F test:
for numerator, Nl-1, for denominator Ns-1
What is mu when sigma is known for single measurements? (normal z test)
3.1
What is mu when sigma is known for averages? (normal z test)
3.2
How do we test if we need an intercept Question?
Doest the value fall within confidence interval containig zero if munot=0?
range of expected results for deciding if we need an intercept:
b=munot+/-tsb
what are the DOF when deciding if we need an intercept?
N-2
how to conclude if we need an intercept test:
if |b|>t*sb, we need an intercept
