Chapter 15- Statistics
15:01A- Review: Representing Data
In representing data, we oftenly use these four ways:
- Table
- Frequency Historgram and Polygon
- Cumulative Frequency Histogram and Polygon
- Box and Whisker Plot
Let's take an example from 'International Math 5' book, exercise 15:01A no. 1
And these are the answers:
15:01B- Review: Analysing Data
To analyse data, we need to know these terms and its meaning:
- Mean: average (Sum of the score divided the number of the score)
- Median: the middle score when the scores are arranged
- Mode: the score repeated the most
Those 3 terms are still the basics. The others below this are the new terms for us:
- Range: difference between the largest score and the smallest score
- Inter-Quartile Range: difference between the 3rd quartile and the 1st quartile, measuring just the middle-50% of the total data
- Standard Deviation
Let's take a random example; here is the unarranged scores:
13, 18, 19, 13, 14, 15, 13, 16, 14, 21, 13, 14
Let's arrange them to make it easy to calculate:
13, 13, 13, 13, 14, 14, 14, 15, 16, 18, 19, 21
Mean:
(13 + 18 + 19 + 13 + 14 +15 + 13 + 16 + 14 + 21 + 13 + 14) ÷ 12 = 15,25
Median:
13, 13, 13, 13, 14, 14, 14, 15, 16, 18, 19, 21 | (14+14) ÷ 2 = 14
Mode:
13, 13, 13, 13, 14, 14, 14, 15, 16, 18, 19, 21 | 13
Range:
21-13: 8
Inter-Quartile Range
13 13 13 | 13 14 14 | 14 15 16 | 18 19 21
16-13: 3
15:02- Standard Deviation
Standard Deviation: the distance of a score and its mean (average)
15:03- Normal Distribution
