2 - Measures of locations and spread Flashcards
1
Q
How is the lower quartile of discrete data found?
A
n/4
if position is a whole number, then take value between this and the next position
if not a whole number, round up and take this position
2
Q
What does using grouped frequency tables rely on?
A
Interpolation
3
Q
What is interpolation?
A
Assuming data values are evenly distributed within each class
4
Q
How is the upper quartile found for grouped continuous data?
A
n/4th data value
5
Q
How are variance and standard deviation estimated when using a grouped frequency table?
A
using midpoint if each class interval
6
Q
How is the mean of coded data found?
A
mean(y) = (mean(x) - a)/b
7
Q
How is the standard deviation of coded data found?
A
sd(y) = sd(x) x a
8
Q
In a histogram, what does area represent?
A
Frequency
