it's a little review for question seven on the homework because this also helps with your lab and of course tests and those types of things um we have the sieve size already given out so this is your stack and then we have the pen and the weight or mass in this case retained is also given and you're asked to find the percent retained cumulative which means all added together percent retained as it's accumulating and then the percent passing for each sieve and then you have to plot the gradation curve of course using excel so you might as well make your data tables in excel and then you're going to find effective size uniformity coefficient and the fine list find this modulus the fm so you already have enough of this information available to you i just want to show you how to set up the chart and plot your gradation curves and so the only way to do that is to get through the cumulative percent retained percent retained and so forth all right so weight retained is given so i'm just going to fill that in you can see i've already prepared a chart for you i made it nice and easy for myself to fill in i like to format things really well we assume that the total has not changed so i'm going to hit equals sum and there we go this is going to add up all of this including the pan and so we have 581.9 grams this step is crucial you must find out what the total is including the pan and again assume that there's no loss in order to figure out percent retained right if i say that i gave out 10 m m's to show and so and 20 m m's to who and who and 30 m m's the he and what and 40 m m so she and we you know you have to add it all together if i say well how many do i have left what what percentage did i give out you wouldn't have any idea unless you knew how many m ms i had to begin with right so that's our assumption so percent retained again i hit equals in order to make this a formula and it's going to be whatever this value is for the sieve size divided by the total and that makes sense right now the cool thing about excel is if i put little dollar signs on either side of the d or whatever letter is part of our my column here then it's actually going to hold both of these both the column and the row static so i can actually go ahead and drag that formula down and the denominator stays the same which is good because that's my total but as you can see the numerator changes as i pull it down now look the cool thing about excel is that it does all the calculations for you as long as you know how to use it and the cool thing about video clips are that you can slow them down right you can go and reverse whatever and you can slow them down so you get these wonderful sound effects to go along with it because you don't see my face today anyway cumulative percent retained really just means you're adding these up together so there are other ways of finding these but since we don't have a lot of data i'm just going to sum up these you can see oh well for the first one yeah cumulatively we only retain 10.23 percent incidentally the way you get percentages if you go up here you hit percent and you can change the number of decimals that you want to show for at the number eight sieve by the time we get there we have 10 plus 14 with some decimals adds up to just over 25 percent so cumulatively we're just keeping track of how far through the sample we have gone look we've already gotten about 71 percent now we're at the number 50 sieve we're almost at 88 percent i'm summing these up if you don't put your equal sign out there you're going to be in trouble now i'm going to do it again just to make sure what's my prediction what should i be hey presto 100 retained that's good now that just is because we assume that the initial sample size was the same as the total mass retained here or weight retained and if you had been given other information like you would have been given in the lab i told you that there was a larger sample size so we had a lost gain ratio to figure out now you don't have that here the lost gain ratio there is no loss so loss is equal to gain or loss is zero um with percent passing is very simple if you retain 10 percent 90 percent passed so all you got to do is take the hundred percent i'm gonna put dollar signs there you could just as easily make it one hundred percent but since we have it there i'll use it and then you subtract whatever was retained do you see what i've done boom all i did was subtract how much was retained minus or or from 100 so now that we have percent passing which was honestly the whole goal here so we had to go through cumulative percent retained which will also help us with the finance module which i won't go into because there's already a video on that for you but now that we have percent passing we are ready to create our excel file or our excel graph so i'm going to first drag and select percent passing and that will set it as one column and then i'm going to hold down control i'm going to go to sieve size i'm going to go all the way down to pan and i'm going to go to insert so i held down control to capture to both of them insert scatter plot and graph now this is wonderful i have this great graph title i guess i could call it percent passing versus um or here let me change this percent passing versus let's call it grain size let's say consistent let's make this a little smaller let's get rid of this key i'm deleting that so we have a nice characteristic curve here you can increase this you move it wherever you want i want to be able to see everything of course but for the sake of this video and and that's good the data is here now it doesn't look like what you would necessarily expect so we can do a few things you can label your axes which you can go into the design tab for that i'm not going to mess around with those but you can play around with your chart layouts that's for you to do but i did want to show you a couple of things a logarithmic scale will help values in reverse order will help it look more characteristic so that's our x-axis and then our y-axis we can done we can go here axis labels low okay and we're looking pretty good looking pretty good and of course you can change grid lines and those types of things you can manipulate this a lot and i definitely would recommend that you put labels on your axes so they make some sense but you can see we have a pretty decent characteristic curve here so everything else that you need is already in video format either during one of our previous session recordings or an additional video that i provided you so i will leave it at that so hopefully that helps