Averages & Spread Flashcards
All 6 cards in this deck
What are the steps to find the median of a set of data?
e.g. 12, 7, 9, 15, 4- Put the values in order: 4, 7, 9, 12, 15
- Pick the middle value: 9
- If there are two middle values, find their mean.
What are the steps to find the interquartile range?
e.g. 2, 4, 6, 8, 10, 12, 14, 16- Order the data and split it into a lower half and an upper half: 2, 4, 6, 8 | 10, 12, 14, 16
- LQ = median of the lower half: 5; UQ = median of the upper half: 13
- IQR = UQ − LQ = 13 − 5 = 8
What is the range of a set of data?
The highest value minus the lowest value — a measure of spread.
What is the modal class?
The class (group) with the highest frequency, i.e. containing the most values.
True or false? A mean calculated from a small sample is less likely to be representative of the whole area than one from a large sample.
True. A larger sample captures more of the variation, so its mean is more likely to represent the whole area.
What does the interquartile range of a data set measure?
The spread of the middle 50% of the values: the gap between the upper quartile and the lower quartile.