Lesson 13- Descriptive Statistics- Measures of Central Tendency & Measures of Dispersion

Question 1

What is the measure of central tendency?

Answer 1

Measures of Central Tendency- inform us about central values for set of data- ‘averages’- typical value

Question 2

List the 3 measures of central tendency

Answer 2

1) Mean
2) Median
3) Mode

Question 3

What is the mean?

Answer 3

Mean- calculated by adding all scores in data set & dividing them by total number of scores

Question 4

What are the evaluation points for the mean?

Answer 4

👎- distorted by single extreme value (anomaly) in data set … value ✖️ true
👍- most accurate measure- takes into account all scores

Question 5

What is the median?

Answer 5

Median- calculated by ranking all scores in order & taking middle value- for even no. of data items take midpoint of the 2 middle values

Question 6

What are the evaluation points of the median?

Answer 6

👎- ✖️ as sensitive as mean- ✖️ all scores used in calculation … unrepresentative of data if scores clustered around ⬆️ & ⬇️ levels
👍- unaffected by extreme scores (anomalies) unlike mean

Question 7

What is the mode?

Answer 7

Mode- most frequent value in data set

Question 8

What are the evaluation points of the mode?

Answer 8

👎- tells us nothing about other scores in data set

👍- mode unaffected by extreme scores

Question 9

What is the measure of dispersion?

Answer 9

The spread of the data

Question 10

What are the 2 measures of dispersion?

Answer 10

1) Range

2) Standard deviation

Question 11

What is the range?

Answer 11

Range- difference between highest ⬆️ & lowest ⬇️ scores in data set

Question 12

What are the evaluation points of the range?

Answer 12

👎- easily distorted by extreme values (anomalies)

👍- quick⚡️ & easy to calculate compared to standard deviation

Question 13

What is standard deviation?

Answer 13

Standard Deviation- average amount that each score differs from mean

Question 14

What are the evaluation points of standard deviation?

Answer 14

👎- ⬆️ difficult to calculate than range

👍- takes into account all scores

Question 15

List the 2 types of ratio

Answer 15

1) Part-to-whole ratio

2) Part-to-part ratio

Question 16

What is a part-to-whole ratio?

Answer 16

Part-to-whole ratio- e.g. no. of ppl who ⬆️ 😊 after eating 🍫 compared to total no. of pps

Question 17

What to a part-to-part ratio?

Answer 17

Part-to-part ratio- e.g. no. of people who ⬆️ 😊 after eating 🍫 compared to those that ✖️