Unit 1(B)

Question 1

What is the median

Answer 1

Middle number of a set of numbers arranged in numerical order

Question 2

What is the mean

Answer 2

Found by summing all terms then dividing by number of terms

Question 3

Characteristic of median

Answer 3

Resistant to extreme values and outliers.

Question 4

Which type of statisic is median used in

Answer 4

Descriptive

Question 5

What type of statistic is mean used in

Answer 5

Inferrential

Question 6

4 ways to describe variability and dispersion

Answer 6

Range
Interquartile range
Variance
Standard deviation

Question 7

What is the range

Answer 7

Diff between largest and smallest value

Question 8

What is the interquartile range

Answer 8

Diff between largest and smallest value after removing the largest and smallest quarters.

Question 9

How much % of data is the IQR

How to calc

Answer 9

Middle 50%

Q3 - Q1 = 75th percentile - 25th percentile

Question 10

What is the variance

Answer 10

Averaging the squared diff of all the values from the mean

Question 11

What is the standard deviation

Answer 11

Square root of variance

Question 12

Adv and disadv of range

Answer 12

Adv:
Quick
Easy to calc

Disadv:
Completely depends on 2 extreme values
Ignores all middle values

Question 13

Adv and disadv of IQR

Answer 13

Adv:
Removes influence of extreme values
Helps catch outliers

Question 14

How to catch outliers via IQR

Answer 14

If a value is 1.5 * IQR less than Q1 or 1.5 * IQE more than Q3 it is an outlier.

Question 15

What does standard deviation give a measure of

Answer 15

measure of the spread of the x-values around the sample mean

Question 16

3 ways to designate positions

Answer 16

Simple ranking
Percentile
Z score

Question 17

What is simple ranking

Answer 17

which involves arranging the elements in some order and noting where in that order a particular value falls

Question 18

What is Percentile ranking

Answer 18

which indicates what percentage of all values fall below the value under consideration

Question 19

What is Z score and what does it do

Answer 19

how many standard deviations a particular value varies from the mean.

Normalizes data

Question 20

When is percentile used (related to the population)

Answer 20

When population size is unknown or irrelevant.

Question 21

Formula for Z score

Answer 21

(X-avg)/sd

Question 22

Avg and s/d of Z score

Answer 22

0, 1

Question 23

Empirical rule - data distribution compared to SD

What distribution shape can it be applied to

Answer 23

68% of data lies within 1 sd
95% of data lies within 2 sd
99.7% of data within 3 sd of the mean

Symmetric bell shaped data

Question 24

Central tendency of a symmetrical/normal curve

Answer 24

Center = mean, median and mode

Question 25

Central tendency of skewed left

Answer 25

Mode < median < mean

Question 26

Central tendency of skewed right

Answer 26

Mode > median > mean

Question 27

What all does a boxplot display

Answer 27

Shows the smallest and largest value. The median, Q1 and Q3.

Question 28

What values are sensitive to outliers vs resistant

Answer 28

Median and IQR resistant

Mean, range, variance, s/d are sensitive

Question 29

What graph is used to compare distributions

Answer 29

back to back stemplot

Question 30

How does changing units/multiplying values by a constant effect all values.

Answer 30

Mean, median, range, s/d remain constant.