 In this video we are going to learn about choosing scale while drawing a bar graph. So you can see some information where we have compiled favorite shake or juice or drink of different number of students. So we have four juices or four types of drinks Guava, Watermelon, Blueberry and Pista. So 23 students like Guava then 35 students like Watermelon, 12, Blueberry and 8 Pista. What we want to do is that we want to draw a bar graph compiling this very information and for that we will draw a y-axis and an x-axis. Now with this we want to plot number of students on y-axis and for that we need to ensure that all the values should be available on the y-axis and that's what we call choosing the scale. Now we could really draw a scale like this. So we could have one student, two students, three students and so on but we won't have enough space for this because we have 35 students as the largest number. So we will have to choose a better scale. We might choose 10 students, 20 students, 30 students and so on but then because the highest value is 35 and the lowest value is 8 our bar graph will look very small and we won't utilize the space well. So we have to plot the units here in a way that the bar graph looks nice and also the space is utilized well. So in this case we will first look at the highest value like we did and the lowest value and we will see if we can plot or divide the y-axis in a way that the lowest bar graph as well as the tallest bar graph will look nicer on the space. So if I start from 0 and make divisions of 5 like this 5, 10, 15, 20, 25, 30 and 35, we will also just plot 40 just for our comfort and now our space is well utilized and we should be able to draw the tallest and the smallest bar graph nicely and now let's write the different shakes or juices. This is for Guava then we will have a space for watermelon, let me make it a little red. I'll just write W80 watermelon then we will have blueberry, let's write blueberry, I'll just write blue and then pista with this pista color and now we will have four bars each one for Guava, watermelon, blueberry and pista and the height corresponding to each of these shakes correspond to number of students that like that drink and now let's plot the bar graph. Let's plot the bar graphs in colors of each of these drinks for Guava we will have this nice pinkish color and the height of this bar will be just above the midpoint of 20 and 25. So just about here let's draw the bar of this height like this and let's color it with this pinkish color. The height for the watermelon bar will be 35 which will exactly correspond to the mark of 35 let's plot it in this reddish color. So this is how the bar will look like let me color it like this then we will plot the bar for blueberry and the height of the blueberry bar is 12 so in 10 to 15 we can draw five divisions this is 11 and this is 12, 13 and 14 and 15. So we want that 12 if we just extend that well here like this and so the blue bar will look like this I would raise the rest of the blue part and we will color the blue bar like this and so the height of the blue bar is 12 and for the pista bar the height is going to be 8 so let's draw the bar of height 8 and height 8 would be between 5 and 10 which would be something like this and let's color it. Just so that we know we will write the number on top of every bar just so that we know that just for our own ease and this is how we have completed the plotting of the bar graph. Now at the end we must show that the number of students increase in this direction it's a good idea to write y axis and x axis all the time when we plot any kind of graphs and the last but not the least we always should write the scale and the scale here means that every unit representing the amount that it is so one unit on y axis is equal to five students and choosing the scale is what we learnt in this video note that we could have numbers ranging from 100 to 500 or 100 to 1000 as well and in such cases the scale would change and it's our job to assign the amount for one unit on y axis in such cases we could choose larger amounts but the objective while choosing a scale is to utilize the space available on the graph nicely so that we do not waste space as well as we do not run out of the space.