Interview
Class notes Consumer math
- Course
- Institution
Class notes Consumer math
[Show more]
Seller
Follow
vs-09rf780039haroldmbrathwaitess
Content preview
MTH1W/8 molenhuis unit: Relationships & Data lesson:One-Variable – Measures of Spread (Quartiles, Box-Whisker Plots)
Central tendency Observe the three data sets on the left.
(mean, median, mode)
can show where the centre a) Do they have the same centre?
of the data is located.
However when we compare b) Do they have the same spread?
two data sets, not only do
we want to know whether c) Which one is more “spread out”?
their centres are relatively
close, but we also want to d) Which one is more “clustered”?
know if their data is spread
out the same way.
One method of measuring spread of data is by quartiles and box-whisker plots.
Ex1. For the data set:
7, 3, 1, 7, 6, 9, 3, 8, 5, 8, 6, 3, 7, 1, 9
(i) Order the data and find the median.
(ii) Find the median of the 1st half of the data.
(iii) Find the median of the 2nd half of data.
The ______________ divides the ordered data set into two halves and these halves are divided in halves again by the ________________.
a) Range measures the distance spreading out between the minimum data and the maximum data.
Calculate the range of this data set.
b) Interquartile Range (IQR): measures the distance spreading out by the middle 50% of the data.
This is calculated by ________________________________________. Calculate the IQR of this data set.
c) A box-whisker plot places the quartiles (Q1, Q2, Q3) and minimum, maximum on an x-scale so that we can visually see how
spread out each quartile (25% of the data) is. Construct a box-whisker plot for this set of data.
Steps of Plotting a Box-Whisker Plot
1
, MTH1W/8 molenhuis unit: Relationships & Data lesson:
Ex2. The following side-by-side boxplots compare the daily times students in year 9 and 12 spend on homework.
a) Complete the table:
Statistic Year 9 Year 12
Minimum
Q1
Median
Q3
Maximum
Range
Interquartile Range
b) True or False: (Justify your answer)
(i) The median of Year 12 students spend about double the time on homework compared to the median of Year 9 students.
(ii) At least 25% of Year 9 students spend less time on homework than all Year 12 students.
(iii) The variety of homework time among Year 12 students is more than Year 9 students.
(iv) There is more variety of homework time in the lower half of the Year 12 group than the upper half.
2
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller vs-09rf780039haroldmbrathwaitess. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
51292 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 15 years now