Lecture 4: Introductions To Histograms & Distributions

Question 1

What is a histogram?

Answer 1

A histogram is a graph illustrating the distribution values in the data set (i.e the frequencies)

Question 2

What’s a bin

Answer 2

Value ranges. Together they cover the full range of data

Question 3

What’s a probability curve/probability density function (pdf lol)

Answer 3

A histogram with a smooth curve when we have an infinite number of values —> the width of the bins can be shrunk to 0 = smooth!

Question 4

Distribution shape: ___——^^——___

Answer 4

Symmetric and unimodal

Question 5

Distribution shape: __—^^—__—^^—__

Answer 5

Bimodal

Question 6

Distribution shape: ____——^^^-_

Answer 6

Negatively skewed (LEFT)

Question 7

Distribution shape: _-^^——___

Answer 7

Positively skewed (RIGHT)

Question 8

THE SKEW IS __________?

Answer 8

WHERE THERE’S FEW!

Question 9

Variables with a floor (hard lower bound) but no ceiling (hard upper bound) tend to have what kind of skew?

Answer 9

RIGHT SKEW!! Few on the upper side :D

Question 10

If a distribution is symmetric and unimodal then the mean, median, and mode are _______?

Answer 10

THE SAME!!!

Question 11

Describe the distribution shape of a skew! (Order of mean, median, and mode)

Answer 11

Mode is the most frequent value so it’s the highest point of the skew!

Then the median is a little lower

Then the skew pulls the mean away from the mode! (Most affected)