What Is And How To Construct Make Draw A Frequency Polygon In Statistics -How To Find Class Midpoint

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  • เผยแพร่เมื่อ 8 ส.ค. 2024
  • In this video we discuss what is a frequency polygon and how to construct make or draw a frequency polygon from a frequency distribution table in statistics.
    Transcript/notes
    Frequency polygon
    A frequency polygon is a graph that provides a visual representation of a data frequency distribution. It uses a line that connects the frequencies of the classes at the midpoints of the classes.
    In a past video we discussed what a frequency distribution is. Real quick, you have a data set, you break the data down into classes or intervals, column 1, you tally up how many data points are in each class, column 2, and you write that number down, which is the frequency, column 3.
    Now we want to take the data that we organized and summarized in the frequency distribution table and show/display it in a graph form, which makes it easier for many people to understand the data, and sometimes, it is easier to see patterns in the data from a graph.
    So, the first thing we are going to do is draw an x and y axis. For the x axis, I am going to put this little squiggle in near the beginning of the line, and I will explain that later in this video. Next we need to label the zero’s, which is going to be where the x and y axes meet.
    Next we need to label both of these axes. The y axis is easy, that is going to be the frequency, or the amount of data points in each class. If you look at the table, the largest number in the frequency column is 25 for the 4th class. So, knowing this, we can draw this line and mark it as 25 somewhere near the top of where our y axis ends. Then we are going to mark 20, 15, 10, and 5 on the y axis. When drawing by hand the increments between these marks doesn’t have to be perfect, just within reason, so that the distances between the marks look symmetrical.
    The x axis is going to represent whatever the data is, so let’s say this data represents sales. But, before we label the x axis we need to calculate class midpoints for each of the classes. The formula for finding the midpoint of a class is the lower class limit + the upper class limit and divide that by 2. So, for class one, the lower limit is 126, add that to the upper limit of 174 to get 300 and divide that by 2 and we get 150 as the midpoint for class 1. Continuing this process for the remaining 6 classes we get, 199, 248, 297, 346, 395, and 444.
    Now that we have the class midpoints, we can label the x axis. This little squiggle hear basically means a broken axis, or it lets the viewer know that there are some values kind of scrunched up here.
    We can start by marking the value of the midpoint of class 1 somewhere to the right of our squiggly line. So, 150 right here. Next we will mark the midpoint of class 2 to the right of the mark for the midpoint of class 1, let’s say right here. And now the midpoint of the 3rd class. When we mark this, we want to mark it so that it has the same distance or width, within reason, as the width between the midpoint markings for class 1 and class 2, so, right about here, and this width or distance is actually representative of the class width. We would continue this process so that all of the midpoints of all of the classes have been marked with the same widths between them.
    Next we need to plot the points for each of the classes. We are going to use the midpoints as the x axis or horizontal values, and the frequencies for the y axis or vertical values. So, for class 1, we have a frequency of 5, and a class midpoint of 150. We find this value on the graph, where these 2 values intersect and plot a point there. For class 2 we have a frequency of 5 and a midpoint of 199. Again, mark the intersection with a dot. And you would continue this process for the remaining 5 classes.
    Now that we have all of our points plotted, we will connect the dots, from class 1 to class 2 to class 3 and so on until we have all of the points connected.
    One last thing that we need to do is draw a line back to the x axis at the beginning and end of the graph. At the beginning of the graph, we are going to pick a point on the x axis that has the same width as the width between the other markings on the graph. So right about here, and we will plot a point and connect the line from this point to the first point. At the end of the graph, we will use the same process. Plot a point on the x axis that has the same width or distance as between the other markings and then connect this point to the previous point.
    Timestamps
    0:00 What Is A Frequency Polygon?
    0:13 Quick Frequency Distribution Review
    0:33 Draw X And Y Axes
    0:48 Label Y Axis
    0:54 Mark Y Axis
    1:18 Label X Axis
    1:25 How To Find Class Midpoints
    2:02 Mark X Axis
    2:40 How To Plot Points
    3:13 Draw Line To X Axis

ความคิดเห็น • 36

  • @iranoutofclevernames3734
    @iranoutofclevernames3734 3 ปีที่แล้ว +30

    Man short and to the point

  • @luvberry2788
    @luvberry2788 6 หลายเดือนก่อน +3

    This is how an educational video should be. Straight to the point 😊 thank you so much it really helped

  • @Nesha_Nati
    @Nesha_Nati 3 หลายเดือนก่อน +2

    Honestly, the best explanation I have seen!

  • @beachboypikihta
    @beachboypikihta 2 ปีที่แล้ว +10

    You explained it better in 4 minutes than my teacher could in an hour 😅

  • @mikuanna
    @mikuanna 5 หลายเดือนก่อน +2

    Omg,your video so very well,it make me can do it^__^ thanks ❤❤❤

  • @pokefinderwar4424
    @pokefinderwar4424 4 ปีที่แล้ว +14

    Best explanation 😁

  • @niharikasrivastava3835
    @niharikasrivastava3835 3 ปีที่แล้ว +3

    So useful session :) I must watch Vidya Guru channel as well for their Reasoning tricks videos. Their classes helped me so well for my Banking clerk exams.

  • @priyojitpaul4347
    @priyojitpaul4347 3 ปีที่แล้ว +1

    Thank u sir, it the best video I ever seen...

  • @shahzadumar5479
    @shahzadumar5479 3 ปีที่แล้ว +6

    Thank u so much

  • @killgamingTM
    @killgamingTM 3 ปีที่แล้ว +1

    It really helped me for my exams

  • @ummeaiman278
    @ummeaiman278 3 ปีที่แล้ว +3

    to the point, great job

  • @Inertia.
    @Inertia. 3 ปีที่แล้ว +1

    Thanks for the help pal

  • @clouds6466
    @clouds6466 2 ปีที่แล้ว +2

    Thank you sooo much😊

  • @AbAb-mm3og
    @AbAb-mm3og 4 ปีที่แล้ว +3

    'liked' Thank you for the video.

  • @khushrajrathore4050
    @khushrajrathore4050 4 ปีที่แล้ว +4

    Thanks bro because of you i able to score full marks in this chapter

    • @whatsupdude2778
      @whatsupdude2778  4 ปีที่แล้ว +3

      Awesome, great to hear that my friend.

  • @bobigaming5176
    @bobigaming5176 2 ปีที่แล้ว +1

    Thank you so much ❤️

  • @angelosarsalides7781
    @angelosarsalides7781 4 ปีที่แล้ว +1

    Thank you so much!😅😅

  • @popcorn_668
    @popcorn_668 4 ปีที่แล้ว +1

    Thanks for that

  • @harshitagaming1278
    @harshitagaming1278 2 ปีที่แล้ว +1

    Thankss u really helped :)

  • @MansoorLashari-ih3bk
    @MansoorLashari-ih3bk 3 หลายเดือนก่อน +1

    Thanks

  • @ourbeautifulmind
    @ourbeautifulmind 10 หลายเดือนก่อน +2

  • @ameetkour6947
    @ameetkour6947 3 ปีที่แล้ว +2

    Suprbbbbbbbbbbb😘😘😘😘😘

  • @sweety3426
    @sweety3426 2 หลายเดือนก่อน

    Upper limit??

  • @snehachatterjee7297
    @snehachatterjee7297 8 หลายเดือนก่อน

    Convert the class intervals into a continuous CI.

  • @mmza5597
    @mmza5597 6 หลายเดือนก่อน

    Don’t we have to make it exclusive

  • @INFINITESHREEYAN
    @INFINITESHREEYAN 4 ปีที่แล้ว +1

    who is from dlf

  • @nilabhraj9845
    @nilabhraj9845 3 ปีที่แล้ว +3

    Thank you for making me fail in exam 🥲🥲

  • @zubairchema7046
    @zubairchema7046 3 ปีที่แล้ว

    😂😂

  • @user-jm6hd1fp6x
    @user-jm6hd1fp6x 5 หลายเดือนก่อน +1

    Slowly sir you are too speed

    • @trug2
      @trug2 2 หลายเดือนก่อน

      Watch in 0.5

  • @Maxyteeee
    @Maxyteeee 2 ปีที่แล้ว

    420 lol

  • @zubairchema7046
    @zubairchema7046 3 ปีที่แล้ว

    This is tooo much

  • @QUAKULUCKYTRAININGCENTER
    @QUAKULUCKYTRAININGCENTER 5 หลายเดือนก่อน +1

    Thanks