Topic 9 Flashcards
(5 cards)
1
Q
T Distribution
A
Fatter tails than normal distribution, giving larger p-values, better for smaller samples. Always centred at 0, single parameter- degrees of freedom, usually = n-1
2
Q
Confidence Interval for T Distribution
A
point estimate +- tdf * x SE where tdf * is the critical value
3
Q
T-Score
A
Tdf = point estimate - null value / SE (null value is the population mean assuming H0)
4
Q
Standard Error for Two Populations
A
SE = √(s1)^2 / n1 + (s2)^2 / n2 and df = min(n1 - 1, n2 - 1)
5
Q
Conditions for t-test
A
Independence between groups and no extreme skew in either
