# Maths unit A:Histograms

HideShow resource information
• Created by: rvsn
• Created on: 18-11-14 22:15
What can't we just draw frequency diagrams with normal frequency?
It is not mathematically correct as the area of the bars gives a false impression of how much data they represent
1 of 9
What is the first step to make a histogram?
Make a new column with class width so how wide the gap between the interval is e.g 150
2 of 9
What is the second step to make a histogram?
Make a column of frequency density
3 of 9
How do you work out frequency density?
frequency/class width
4 of 9
How do you work out frequency?
frequency density x width
5 of 9
What is the third step to make a histogram?
plot x-axis with the class and plot y-axis with frequency density
6 of 9
How do you find the median from a histogram?
1.(total frequency)/2 2. Find area bars, get frequency, add them until you're on or above the number to get the group. 3.Find the extra and work out width of block worth the frequency by rearranging equation,cumulative frequency=ans
7 of 9
How do you find IQR?
Do as normal but remember to convert frequency to exact width to get the exact IQR
8 of 9
How do you find the mean from it?
Do the fx method
9 of 9

## Other cards in this set

### Card 2

#### Front

What is the first step to make a histogram?

#### Back

Make a new column with class width so how wide the gap between the interval is e.g 150

### Card 3

#### Front

What is the second step to make a histogram?

### Card 4

#### Front

How do you work out frequency density?

### Card 5

#### Front

How do you work out frequency?