Descriptive Statistic + Levels Of Measurement

Question 1

What is descriptive statistic

Answer 1

Summarise the findings collected

Question 2

Mean

Answer 2

Add all score then divide by number of sets
-use for interval + ratio data

Adv:
Use all data - does not exclude results

Disadv:
If there is extreme + anomalous results = misleading representation of data - sensitive

Question 3

Median

Answer 3

Put all numbers in order and select only the number in middle - ordinal data

Adv:
Avoid extreme values

Disadv:
Less reliable in smaller sample
Exclude results

Question 4

Mode

Answer 4

Select data that appears the most time - nominal data

Adv:
Avoid extreme result

Disadv:
Crude measure - ignore result
If too many mode values not useful

Question 5

Nominal data

Answer 5

Answers are in categories and usually tally up
-number of boys and girl
-lowest level of measurement

Question 6

Ordinal data

Answer 6

Ranked data, data are put in hierarchy (ascending + descending order) but intervals in between data not related
-degree of agreement (1-5)
-based on opinions

Question 7

Interval/ ratio data

Answer 7

Data with measurement in between
-highest level of measurement
-ratio has true zero (weight, height)
-interval no true zero (temperature)

Level measurement can go down but not up

Question 8

Measure of dispersion

Answer 8

Standard deviation - how spread out data are from mean
1) Find mean of total score for x with line on top
2) Raw score of each category - mean
3)square it
4)add all answer up
5)divide total by number of sets of score - 1
6) square root answer

Range

Highest value - lowest value

Question 9

Standard deviation graph

Answer 9

https://www.thoughtco.com/thmb/qmSnmY_b1ztjvvdp-QhdT4-DA8c=/1500x0/filters:no_upscale():max_bytes(150000):strip_icc()/calculate-a-sample-standard-deviation-3126345-v4-CS-01-5b76f58f46e0fb0050bb4ab2.png