Find suitable value of Median and Range for given box-whisker plot

In summary, to find the median and range from a given box-whisker plot, identify the median by locating the line inside the box, which represents the middle value of the dataset. The range is determined by calculating the difference between the maximum and minimum values indicated by the whiskers at both ends of the plot. The box represents the interquartile range, highlighting the spread of the middle 50% of the data.
  • #1
chwala
Gold Member
2,752
387
Homework Statement
see attached - This is from an As level- statistics past paper question...
Relevant Equations
stats
I do not seem to understand this question nor the Ms. I understand the box-whisker plot and its relationship to quartiles of which ##Q_2## is the Median.

This question is from an As level- statistics past paper question.

1713258963152.png


1713258990858.png




1713259012219.png
 
Last edited:
Physics news on Phys.org
  • #2
Jiang is studying the variable Daily Mean Pressure from the large data set.
Is the large data set or information about it given in this problem?
 
  • #3
Mark44 said:
Is the large data set or information about it given in this problem?
It is not given.

1713394786476.png
 
  • #4
The question author wrote these statements:
  • "Jiang is studying the variable Daily Mean Pressure from the large data set."
  • "Using your knowledge of the large data set,..."
  • "(You are not expected to have memorised values from the large data set. ...)"
I infer from them that there is some data set to look at.
How else are you expected to know that values of 990 to 1030 are suitable, or that the range of values [a, b] is such that |a - b| is somewhere between 10 and 50?
 
  • Like
Likes chwala
  • #5
Here's the test booklet that contains this question. On the front page it indicates "you must have a copy of the Pearson Edexcel LDS or 'Large Data Set' and a calculator". However, there does not seem to be a copy of it floating around somewhere on the internet, just the test booklet.
 
  • Love
  • Informative
Likes Mark44 and chwala
  • #6
docnet said:
Here's the test booklet that contains this question. On the front page it indicates "you must have a copy of the Pearson Edexcel LDS or 'Large Data Set' and a calculator". However, there does not seem to be a copy of it floating around somewhere on the internet, just the test booklet.
Noted. I was not aware of that. Thanks for keeping me informed.
 
  • #7
Each of the English exam boards produces a "Large Data Set" to support questions in Mathematics/Statistics papers. Teaching these syllabuses should include many exercises giving the student familiarity with the data.

Here is the current Edexcel LDS: I am not sure if this has changed from the one used in 2021 when that paper was set.
 
  • Informative
Likes chwala

FAQ: Find suitable value of Median and Range for given box-whisker plot

What is a box-whisker plot?

A box-whisker plot, also known as a box plot, is a graphical representation of a dataset that displays its central tendency and variability. It shows the median, quartiles, and potential outliers, providing a visual summary of the data distribution.

How do I find the median from a box-whisker plot?

The median is represented by the line inside the box of the box-whisker plot. It divides the dataset into two equal halves, with half of the data points below it and half above it. You can directly read the median value from the plot.

How is the range determined from a box-whisker plot?

The range is calculated by finding the difference between the maximum and minimum values represented by the whiskers of the box-whisker plot. The formula is: Range = Maximum Value - Minimum Value.

What do the quartiles represent in a box-whisker plot?

The quartiles are values that divide the dataset into four equal parts. In a box-whisker plot, the lower quartile (Q1) is the left edge of the box, the median (Q2) is the line inside the box, and the upper quartile (Q3) is the right edge of the box. These quartiles help to understand the spread and center of the data.

Can I estimate the values of median and range if the box-whisker plot is not labeled?

Yes, you can estimate the values of median and range from a box-whisker plot even if it is not labeled, by visually assessing the position of the median line and the endpoints of the whiskers. However, for precise calculations, it is best to have the actual values indicated on the plot.

Similar threads

Replies
9
Views
3K
Replies
1
Views
1K
Replies
2
Views
1K
Replies
15
Views
1K
Replies
7
Views
1K
Replies
10
Views
2K
Replies
14
Views
2K
Replies
2
Views
2K
Back
Top