HistogramsIB MYP Maths Extended: Flashcards

What these 13 flashcards ask

What does the area of a bar in a histogram represent?
What is the height of a bar on a histogram?
Formula for frequency density?
Formula for frequency from a histogram?
Class width of 10<t\le20?
Is there a gap between bars in a histogram?
What type of data does a histogram show?
Why do we need frequency density?
Does the tallest bar have the greatest frequency?
Class 2<t\le5 has frequency 21. Frequency density?
A bar has width 10 and height 3.5. Frequency?
How do you estimate the frequency of part of a class?
What should the vertical axis of a histogram be labelled?

Exam questions on Histograms

A café in Seoul records how long $t$ minutes 70 customers wait to be served. The results are: $0<t\le2$ : 8 customers; $2<t\le5$ : 21 customers; $5<t\le10$ : 30 customers; $10<t\le20$ : 11 customers. The data is to be shown in a histogram.
Find the frequency density of the class $10<t\le20$ .2 marks
A student investigates classes of different widths that each have frequency 12. The class $0<x\le1$ (width 1) has frequency density 12. The class $1<x\le3$ (width 2) has frequency density 6. The class $3<x\le7$ (width 4) has frequency density 3. The class $7<x\le15$ (width 8) has frequency density 1.5.
Use the rule to find the frequency of a class of width 6 with frequency density 2.5, and the frequency density of a class of width 3 with the same frequency.2 marks
A histogram shows the ages $a$ in years of the people who visited a museum in Cape Town on one day. The frequency densities are: $0\le a<10$ : 2.4; $10\le a<20$ : 3.5; $20\le a<40$ : 4.2; $40\le a<70$ : 1.5.
Find the number of visitors in each class and the total number of visitors.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).