4.3 Measures of central tendency and dispersionIB Maths: Applications and Interpretation SL: Flashcards

What these 13 flashcards ask

Formula for the mean of n values?
How do you find the median of an even number of values?
Which average is least affected by outliers?
How do you estimate the mean of grouped data?
Mid-interval value of the class 20\le x<30?
When can you use the modal class?
What is the variance in terms of standard deviation?
How should standard deviation be found in exams?
At SL, is the data set a population or a sample?
Which measures are unchanged when 3 is subtracted from every value?
What happens when every value is doubled?
Why might GDC and hand-calculated quartiles differ?
Formula for IQR?

Exam questions on 4.3 Measures of central tendency and dispersion

A hockey team scores the following numbers of goals in 10 matches: 2, 0, 3, 1, 4, 1, 2, 5, 1, 1. Treat these 10 matches as the whole population.
Use your GDC to find the standard deviation and the variance of the number of goals.2 marks
The waiting times, $t$ minutes, of 50 patients at a clinic are recorded. $0\le t<10$ : 6 patients; $10\le t<20$ : 14 patients; $20\le t<30$ : 18 patients; $30\le t<40$ : 9 patients; $40\le t<50$ : 3 patients.
Estimate the mean waiting time.2 marks
The daily maximum temperature in a town over a month has mean $30\,^\circ$ C and standard deviation $4\,^\circ$ C. A visitor converts each temperature to degrees Fahrenheit using $F=1.8C+32$ .
Find the mean temperature in degrees Fahrenheit, and write down the variance of the temperatures in degrees Celsius.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).