W4

Question 1

Histograms

Answer 1

visual representation of frequency distribution where frequencies are represented by bars

Question 2

Normal curve

Answer 2

bell shaped curve
representation of distribution of scores
mean median and mode are the same
if they are different the curve is skewed to one side or to another

Question 3

Range

Answer 3

large rage - big variability
limitations -
only take into account extreme values

Question 4

IQR

Answer 4

Q3-Q1

Question 5

Outliers

Answer 5

Lower -> Q1 - 1.5(IQR)
Higher -> Q3 + 1.5(IQR)

Question 6

Z- scores

Answer 6

show how extreme or common an observation is

the larger the z score, the further its value from the groups mean
the lower the z score, the closer it is to the mean

between -2 and 2

z score of 0 = no deviation from mean

Question 7

Variance and Stdev

Answer 7

extent to which values in a data set vary

the larger the stdev - wider the range of values on either side of the mean

variance = sd^2

Question 8

Variability

Answer 8

how much scores differ from the mean - spread of dispersion

how different the scores are from one another

Question 9

Pearsons correlation coefficient

Answer 9

expresses the direction and strength of a linear correlation with one number

+ r = + correlation
- r = - correlation

number will always lie between -1 and 1
-1 = perfect neg
1 = perfect pos

0 = no correlation