Standard deviationIB MYP Maths Extended: Flashcards

What these 13 flashcards ask

What does the standard deviation measure?
What does a small standard deviation tell you?
What does a large standard deviation tell you?
What is the standard deviation of a list of equal numbers?
Symbol for the population standard deviation?
What is the variance?
What units does the standard deviation have?
How do you find a standard deviation in MYP?
How do you enter a frequency table into a calculator?
Mean of a frequency table?
What are the two measures you use to compare two data sets?
Two groups have the same mean. Group P has \sigma=2 and Group Q has \sigma=9. Which is more consistent?
What happens to the standard deviation if you add a value equal to the mean?

Exam questions on Standard deviation

Five students in Singapore record how many minutes it takes them to solve a puzzle: $4,\ 6,\ 7,\ 9,\ 14$ . Use technology and the population standard deviation $\sigma$ where needed.
A sixth student takes exactly $8$ minutes. State the new mean and find the new standard deviation. Say whether the spread has increased or decreased.2 marks
A teacher investigates how the standard deviation changes as values spread out. Each list below has five values and mean $10$ . List P is $8,9,10,11,12$ with standard deviation $1.41$ . List Q is $6,8,10,12,14$ with standard deviation $2.83$ . List R is $4,7,10,13,16$ with standard deviation $4.24$ . (All standard deviations are given to 3 significant figures.)
List T is $5,7.5,10,12.5,15$ . Use the pattern to predict its standard deviation, then verify your prediction using technology.2 marks
Two courier companies in Nairobi each make five deliveries to the same shop. The delivery times in minutes are: Company X: $20,\ 24,\ 28,\ 32,\ 36$ . Company Y: $26,\ 27,\ 28,\ 29,\ 30$ .
Find the mean and the standard deviation of the delivery times for each company.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).