Measures of central tendency and dispersion Flashcards Preview

BMS1042: Biostatistics > Measures of central tendency and dispersion > Flashcards

Flashcards in Measures of central tendency and dispersion Deck (10)
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1
Q

measures of central tendency

A

mean median mode

2
Q

bimodal

A

two modes

3
Q

multimodal

A

three or more modes

4
Q

measures of dispersion

A

range
interquartile range
standard deviation

5
Q

how to calculate IQR

A

find median (Q2)
find median of minimum and Q2 (Q1)
find median of maximum and Q2 (Q3)
IQR = Q3 - Q1

6
Q

how to calculate standard deviation

A

calculate (value - mean)^2
calculate the average of this (variance)
calculate square root of this (standard deviation)

7
Q

normal distribution

  • relationship between mean, median and mode?
  • what measure of central tendency/dispersion to report?
A

mean = median = mode

mean and SD

8
Q

negatively/left skewed

  • appearance
  • relationship between mean, median and mode?
  • what measure of central tendency/dispersion to report?
A

outliers to the left/negative; mode to the right
mode > median > mean
report median and IQR

9
Q

positively/right skewed

  • appearance
  • relationship between mean, median and mode?
  • what measure of central tendency/dispersion to report?
A

outliers to the right/positive, mode to the left
mode < median < mean
report median and IQR

10
Q

when you’re comparing two distributions and atleast one is skewed, what do you report

A

median and IQR