Year 9 Statistics the distribution of data set

hello D&I welcome back to mr. Chang video how are you today in mess especially in statistics we won't be focusing on the distribution of data set distribution that said pretty much talking about how the data is spread when you put them on the graph okay and as if we give you color bra or line of frequency table most of the time how we actually look so the learning objective today because you will be able to find any peace you will be able to list and also describe some of the common distribution of data set the keywords that you will learn from this video is our data set data set distribution so that I'll say three months is you have set of data that following back followed by earth through survey so if you look at the height of people type of student at school so you you will collect data and does that work in your data distribution means how it spread how it looks okay how the data spread the people you actually organize the data at their foot other common graph for example symmetric distribution or for 264 earth are specific term in the distribution for the distribution of the data set so you have symmetric distribution by mortal distribution negatively skewed distribution and positively skewed distribution okay those are the those are actually the shape of data so let's look into it the shank or distribution of sent often become clearer if the curve is drawn to the graph of the data okay so we have let's say we have set of data of all the students the height of all student at 12 spoon when you organize and put them on the graph you will you will you will see pattern the pattern become clearer when you throw curve okay at the top and by following the data okay so they are actually quite few common distribution let's look at that so the first one is symmetry distributor symmetry means it is symmetrical so it moves each site is in looks the same so one half of the graph is approximately mirror image of another half so right here we have symbol symmetry symmetric distribution so one of the very good example is the height of student at high school if you're going to survey everyone and measure the height and actually lay them out on the graph you will see let's say these are you will see this graph this is also called the bell curve drop all right fail perf graph so it's kind of look like fail okay and want to go sleep in there and there are two Paula in okay so obviously you will have people who are two hundred centimeters and you will have on the left hand side you'll have people who are shorter who will be shortest maybe 140 centimeters okay but they are they are kind of bring their kind of red so that's why they're the frequency is lot shorter and what happened is after you've done your survey and reorganizing you will realize there are quite few people have it is in the middle well will say probably 170 centimeters so that what that means is it is most commonly occurring right okay and this kind of distribution is actually very kind of nice to have by you yeah it's really nice to have this kind of this abuse of you you will see it is quite you see it is like bell curve okay and we only have one peak okay one peak which is right there by moro the second one is bimodal distribution find of bimodal means to binding to so then one way to is easily with bad berries if you see bimodal distribution means you see to peak okay to pick in the data so some of the other told that if this is the height of now wanna say hi will pick something like how busy takeaway shop is throughout the day okay so yes if I'm gonna do this would guess that this will be lunch time and this will be during dinner time okay the distribution has true distinct okay has to stiff me we got distribution has food this thing chic that means too high so it will be something like time of people going to get their food the takeaway shop so you will see to pick lunchtime and dinnertime third and fourth one is the one that always had quite often get confused with myself even so you have to actually be really clear this the first one is called negative please stretch site as negatively skewed distribution okay what negatively skewed means the left side we are if you are on the graph always not consume matter there is the middle so that is the middle that's the middle okay against the doodle dance the noodle anything from the mid of the left from the middle is negative side anything make right from the middle is the contradictory side so negatively skewed distribution means the negative side is actually stretch out means it's cute towards the negative side and on the other hand positively skewed means the dry or positive side without scratch out so if you look at least this positive side is actually good stretch out okay so it means what if you get this kind of data it can be deep means that there are more people do their 20 on this side more sample size whatever that are you collecting you have collected it means there water down on this side and for positively skewed it means are there more travel site on the deaths of the left hand side so it can be bit confused using just have to remember- least you means the left hand side the negative side and each stretch out positive means you'll need the course website of the middle which is the right hand side has been stretched out the data okay so yep probably one of the example Wolfie if I'm going to go with this negatively skewed distribution will be so it can be how many people if you survey how many people like to play basketball how many people can play basketball compared to dancing just for trying lot don't know what that is it's just an example so how many people if you're doing survey and you have more people on this side if this is si means have basketball site means there are more people know how to play basketball okay unless people know how to dance for this one e4 positively skewed distribution you can have their mob keep their more how many happy time do people with laundry over their lifetime so what happenes on the positive side people winning and negative flight people not really so when you stretch them out on the right hand side it means there are less people really okay there are only selective few people have one longer throughout the lifetime competitive of this site where they are many who has one at all okay so just but the thing that you have to take away today is there for ways to present data but not for way the data is distributed by are distributed but you have symmetric distribution when you have only one pic and it is right in the middle and by moto means you're true picked two distinct things to do swing high and negatively skewed means the data on the left hand side when Megan if has been stretch out and positively is give me data on the right hand side has been stretcher okay that's what the full combat distribution of Darla so if we're gonna do quick exercise on this to actually and show you how we actually look like if you're going to do it so the question here is 4 45 people will ask how many times they have visited the doctor this year the result are given in frequency table alongside first you have to display this information on the column graph so column graph look something up then you have like many columns so number visit frequency so if I'm going to throw this okay so I'm gonna go one two three one two six numbers or frequency the highest is 90 so if broader look like this sorry not the best following the one two three four five six seven 90 nice high numbers of frequency and number visit is the maximals or with the number of visit so 0 here and then you know people who never went to top this 0 which is to stretch it up you okay if will let's get out really fly that's 0 and 0 1 2 3 4 5 6 7 sightings so zero there are six people will never be the doctors the whole year and one time for one there eight people went to doctor once is here and then nine people who wear the doctor twice this year ok always do in the middle as in between that line between this number sorry and seven people when you don't fit in time for six people when the doctors four times as you can kind of see it means that they are people who are 65 their knots and majority people on the sick side mean second artists is often once or twice and then four people isn't dr. five times two peoples ended up the six times and set to be blend of the seven times hope they're all right and one person when the doctor time so you're gonna make it look pretty it one looks like this and if go back bit clean your grass look like is isn't that nice pink color Isabel actually quite enjoying doing this chemical is actually kiss you guys like step by step how to create your column graph is you don't already know I'm do it and also how the interpreter so there you go on down with that so as you can see if I'm gonna drop curse ok because would be like so what the curse help me is the data is positively skewed okay so which is it looks like this it means the right hand side of the data has been stretch out right of positive side side of data is Fred how so what that means is there are people who went to doctors this year but lot of them are only or for one or twice Sam and they are active as six people who being even though the doctor this year from the survey so it tells you that many people are generally healthy and yeah there are few there are but few people who rather see doctors quite more seven eight times and yeah that's what the data tells you and how you can read the data through the distribution okay and also by look like just by giving that curve you can actually give you of the idea of which direction or thread the data is ready so that's it for this video's please write down their nose and yeah hope you learned something about the distribution of data sets and remember therefore type to them symmetric distribution bimodal distribution negatively skewed distribution and positively skewed distribution well hope you enjoy these videos write down any questions you have and make sure to record your notes for future reference peace out bye