Measures of Centre
Name the three most precise mathematical terms for calculating the 'average'?
Mean, median and mode
Name the two commonly used measures of spread
Range and Interquartile Range
What is a group of flamingoes called?
Flamboyance
A survey conducted on an entire population
Census
How do you calculate the mean?
Sum of all the values divided by the total number of values
How do you calculate the range?
Range = the highest number - the lowest number
What is Harry Potter's Middle Name?
James
How is data collected from surveys represented?
Data collected can be represented in a histogram
What are the steps for working out the median?
First put the numbers in ascending order, then select the middle number. If there are two middle numbers you will need to find the mean of the two numbers to calculate the median.
Does an outlier affect the range and interquartile range?
An outlier will affect the range but not the interquartile range
What is the female smurf called?
Smurfette
How many ways can data be represented in a histogram and name them?
There are three ways data can be represented in a histogram.
1. Symmetric
2. Skewed
Give a full description of the mode
The mode is the most common value, i.e. the one with the highest frequency. There can be more than one mode.
What is the range of the set of scores below?
7 5 1 6 7 5 7 10 7 6
Range = highest number - lowest number
Highest number = 10
Lowest number = 1
10 - 1 = 9
Range = 9
What year did Nike first use the swoosh logo?
1971
What effects the accuracy of a survey's findings/conclusions?
- Sample size
- Whether the sample is representative of the larger group
- Bias
- Measurement errors
- Outliers
Give a definition of an outlier and explain which measures of centre are effected by an outlier.
An outlier is a data point that is significantly smaller or larger than the rest of the data. The mean can be significantly affected by an outlier.
Name all the steps required in working out the interquartile range.
- Sort the data into ascending order
- Split the data into two equal sized groups
- If there is an odd number of values remove the middle one
- Find the median of the lower quartile
- Find the median of the upper quartile
- Minus the lower quartile from the upper quartile
Which metal is heavier, gold or silver?
Gold
If a data distribution is symmetric what two measures of centre will be approximately equal?
The mean and median will be approximately equal if the data is symmetric.