To find the median value, draw a line across from the middle value of the table. This is strangely fun. You have two to the left and two to the right so the median of the second half is Sort the data from least to greatest and then find the interquartile range of the data set and I encourage you to do this before I take a shot at it. So we have a seven. Find the interquartile range of the data in the dot plot below. In order to calculate this value we must first understand what the lower quartile, median and upper quartile are:

Let’s see, I have one, two, three, four, five, six, seven, eight, nine, 10 numbers. A cumulative frequency diagram is also a good way to find the interquartile range , which is the difference between the upper quartile and lower quartile. So the middle of the first half is five. Reading from the graph, the lower quartile is We have two albums with nine songs so we have two nines. Interquartile range is just going to be the median of the second half, 12 minus the median of the first half, nine which is going to be equal to three.

No fives but there is a six. Cumulative frequency diagrams A cumulative frequency diagram creates a running total of the amounts within a table. So the middle two numbers look like it’s these two 10s here because I have four to the left of them and then four to the right of them and so since I’m calculating the median using two numbers, it’s going to be halfway between them. Find the interquartile range of the data in the dot plot below.

### Range and box-and-whisker plots – WJEC – Revision 2 – GCSE Maths Numeracy (WJEC) – BBC Bitesize

The middle two numbers are 12 and Mean and standard deviation versus median and IQR. So this is just representing the data in a different way but we could write this again as an ordered list so let’s do that.

In the example above, there are 40 babies in the table. Finding the interquartile range A cumulative frequency diagram is also a good way to find the interquartile rangewhich is the difference between the upper quartile and lower quartile. If you’re seeing this message, it means we’re having trouble loading external resources on our website.

### Interquartile range (IQR) (video) | Khan Academy

A watxh frequency diagram creates a running total of the amounts within a table. Well, if you have five numbers, if you have an odd number of numbers, you’re gonna have one middle number and it’s going to be the one that has two on either sides. The average of 12 and 14 is going to be 13, is going to be In order mahts calculate this value we must first understand what the lower quartile, median and upper quartile are: So the interquartile range is the difference between the upper quartile and lower quartile.

A high value for the interquartile range shows that the data is spread out. So let’s see, the lowest number here looks like it’s a four. So 10, 10, 10 then we have an I have the middle of the second half, Quartiles and interquartile range The interquartile range is another measure of spread, except that it has the added advantage of not being affected by large outlying values. If you took 12 plus 14 over two, that’s going to be 26 over two which is equal to 13 but an easier way for numbers like this, you say hey, 13 is right exactly halfway between 12 and Ranhe low value for the interquartile range means the data is closer together or more consistent.

You will notice that the fact there is an outlier in this data 60 which has had no bearing on the calculation of the interquartile range. So the interquartile range for this first example is going to be 13 minus five.

To find the upper quartile, find of 40, which is rznge 30th value. Let me write those, we have two nines then we have three 10s. The value the upper quartile is the median of the upper half of the data. There are 7 pieces of data, so: Reading from the graph, the upper quartile is Consider the following data: Let’s see, I have one, two, three, four, five, six, seven, eight, nine, 10 numbers.

The interquartile range is a measure of how spread out the data is. Visually assessing standard deviation.

Well, the average of 10 and 10 is just going to be Let’s do some more of these. So there you have it.

## Interquartile range (IQR)

I have four numbers. We have an So the average of four and six, halfway between four and six is five or you could say four plus six is, four plus six is equal to 10 but then I wanna divide that by two so this is going to be equal to five. This is strangely fun.

The middle of the second half minus the middle of the first half which is going to be equal to eight.

The second number is The sixth number is This has two to the left and it has two to the right. So the median of the first half, the middle of the first half is nine right over here and the middle of the second half, I have one, two, three, four, five numbers and this 12 is right in the middle. A cumulative frequency diagram is drawn by plotting the upper class boundary with the cumulative frequency.

Interquartile range is just going to be the median of the second half, 12 minus the median of the first half, nine which is going to be equal to three. To find the median value, draw a line across from the middle value of the table.