Compute median from the below histogram.

90 data points
#$44 +45=89/2=44.5$$
The median would be smack-dab in the middle 44 and 45.
 
But that is very time consuming so you don't really want to do that.
Can you see that the data points in position 1 to 8 are 35.
The next 9 data points, ie data points in position 9 to 17, are 36.
Can you continue that way until you identify which data points are in positions 45 and 46?
 
Good morning. I listed all data points


(8) 35, 35, 35, 35, 35, 35, 35, 35,

(9) 36, 36, 36, 36, 36, 36, 36, 36, 36,

(14) 37, 37,37, 37, 37,37, 37, 37,37, 37, 37,37, 37, 37,

(19) 38,38,38,38, 38,38,38,38, 38,38,38,38, 38,38,38, 38, 38,38,38,

(15) 39,39,39,39,39,39,39,39,39,39, 39,39,39,39,39,

(10) 40,40,40,40,40, 40,40,40,40,40

(7) 41,41,41,41,41,41,41

(6) 42,42,42,42,42,42

(2) 43,43

The data points in italics are in positions 45 and 46, that is, if I understood your instruction correctly
 
Yes but Harry also said that is the time consuming way to do it.

The number of data points SUMMARIZED in the histogram is
8 + 9 + 14 +19 + 15 + 10 + 7 + 6 + 2 = 90.

That is an even number so we know that the median is the mean of the 45th and 46th data points (when all 90 data points are sorted in ascending or descending order).

The histogram's categories are, reading left from right, in ascending order.

In which category is the 45th data point?

In which category is the 46th data point?

So what is the median?

That is all there is to it.
 
JeffM said:
Yes but Harry also said that is the time consuming way to do it.

The number of data points SUMMARIZED in the histogram is
8 + 9 + 14 +19 + 15 + 10 + 7 + 6 + 2 = 90.

That is an even number so we know that the median is the mean of the 45th and 46th data points (when all 90 data points are sorted in ascending or descending order).

The histogram's categories are, reading left from right, in ascending order.

In which category is the 45th data point?

In which category is the 46th data point?

So what is the median?

That is all there is to it.
Click to expand...

then the median is in category 19
because position 45th and 46th are in the 38 range of age in months.
 
eddy2017 said:
then the median is in category 19
because position 45th and 46th are in the 38 range of age in months.
Click to expand...
I think you have the right answer, but it is not described well.

The median is 38, not 19. There are 19 data points with a value of 38.

We find the median by counting ordered data points, but the median is not a number of data points.
 
JeffM said:
I think you have the right answer, but it is not described well.

The median is 38, not 19. There are 19 data points with a value of 38.

We find the median by counting ordered data points, but the median is not a number of data points.
Click to expand...
Thank you, Jeff. Thanks to all. It is been a difficult exercise. this is the first I do of this kind with a histogram and all.
if you know of another one and can send it to me I will appreciate it. Need to practice this. it is not your usual mean median range type of exercise.
I am printing it out and studying it. it is a good reference for future problems like this.
 
Thanks to Dr Khan, BBB and special thanks to Harry the cat for all the advice given and all the patient given
 
Subhotosh Khan said:
Those are the heights of the rectangles that comprise the histogram.
Click to expand...
Dr Khan, I am watching again Dc Khan video and try to find any meaning in what you said were the numbers he wrote on the bar. you said here they are the heights of the rectangles that comprise the histogram.
Would you care to give me an example, let's say
why does the second interval have 9 data points?. Why?
I tried to see if what you said gave me any clue but I got none.
thanks a lot for any help.
 
Eddy

Do you have any idea how hard it is to answer a question going back some 50 posts about a screenshot from a video when you talk about a number on a “bar.”

There are at least four numeral 9’s on that screenshot and they come from different times in the video.
 
eddy2017 said:
Dr Khan, I am watching again Dc Khan video and try to find any meaning in what you said were the numbers he wrote on the bar. you said here they are the heights of the rectangles that comprise the histogram.
Would you care to give me an example, let's say
why does the second interval have 9 data points?. Why?
I tried to see if what you said gave me any clue but I got none.
thanks a lot for any help.
Click to expand...
I second Jeff's complain.

My interpretation is that there were 9 subjects with age 36 months

and (although you did not ask for these) there were 8 subjects with age 35 and there were 14 subjects with age 37 month.

1645809313132.png
 
Subhotosh Khan said:
I second Jeff's complain.

My interpretation is that there were 9 subjects with age 36 months

and (although you did not ask for these) there were 8 subjects with age 35 and there were 14 subjects with age 37 month.

View attachment 31317
Click to expand...
Subhotosh

I do not think he is even asking about the actual problem. I think he asking about a screenshot from the middle of a video by Sal Kahn on a completely different problem. I greatly admire Sal Khan, but this not one of his best videos. And I have no idea of what Eddy is asking about.

He should start a new thread, link to the video, and give us a time marker of where he gets lost.
 
JeffM said:
Eddy

Do you have any idea how hard it is to answer a question going back some 50 posts about a screenshot from a video when you talk about a number on a “bar.”

There are at least four numeral 9’s on that screenshot and they come from different times in the video.
Click to expand...
Jeff, I respectfully disagree if I can disagree with something you and Dod say:
I am putting the timer on the video at exactly 2:27. At exactly this time, he writes the number of data points each bar has. That is why I was asking about. How did he get those?.
You and Doc K do not have to watch the video to know that.
if you want me to open a thread, I will, but it is only that I need because this video will give me a good background for this type of exercise we have done here.
 
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