STATISTICAL HYPOTHESIS TESTING Flashcards
a graphical representation of the probability that the data collected distributes itself normally.
Gaussian Curve (a.k.a Normal distribution curve or the Probability distribution curve)
The Gaussian curve has the following characteristics
- The mean is always at the center of
the curve - It must only have one mode (peak)
- Must have a predictable SD
- It must be symmetric.
(Stephanie, 2014)
The data is said to be normally distributed if
both symmetrical and mesokurtic
Skewness
imbalance in the distribution of data
relative to the mean
represents a
data set that has extreme values larger than the
mean which brings the mean up having a value
greater than that of the median
positively skewed curve
opposite of that in all respects. It would represent a data
set that has extreme values which are low, this means that the mean is also low and that the median
and the mode is both greater than the mean
negatively skewed
the 4th moment in statistics. It measures the peakedness (+ leptokurtic) or the
flatness (- platykurtic) of the data set. Normally distributed data should be mesokurtic having a value
of 3.
Kurtosis
considered to have positive kurtosis and appears to have a higher
peak and a longer tail
leptokurtic curve
considered to have negative kurtosis and appears to have a low
peak if any, and shorter tails
platykurtic curve
assumption about a population parameter which may or may
not be true
statistical hypothesis
proves it true or not true
Hypothesis testing
type of hypothesis stated in the positive form
alternative hypothesis
assumes that the values being tested are not equal, either one or more
of the values are greater and/or lesser than the other
alternative hypothesis
negates it.
null hypothesis
assumes them to be
equal.
null hypothesis
