QM 716 Stats and Analysis Chapter 2

Question 1

Histogram

Answer 1

special graphs that can help us see how and where our data is concentrated

Question 2

How do you create a histogram?

Answer 2

1. Divide the range of the data into intervals of equal width
2. count how many data values fall into each interval
3. make a bar chart where the height of a bar is equal to this count. ‘

Question 3

Total area of the histogram represents ____% of the data

Answer 3

100%

Question 4

mode on a histogram

Answer 4

The value below the highest peak of the histogram

Question 5

bimodal shape

Answer 5

A shape with two distinct peaks

Question 6

True or false: bar charts are the same as histograms

Answer 6

FALSE!

Question 7

spikes in histograms represent _______.

Answer 7

high concentrations of data.

Question 8

If the histogram has a “tail,” to the right, then the avg. will be…..

Answer 8

to the right of the median

Question 9

If the histogram has a “tail,” to the left, then the avg. will be…..

Answer 9

to the left of the median

Question 10

How do you get each quartile and the IQR?

Answer 10

• To get the 1st quartile: take the data below the median and look at the median of the median.
• 3rd quartile: median of values above the median
• second quartile=median
• Interquartile range (IQR)= 3rd quartile-1st quartile

Question 11

Emperical Rule

Answer 11

for many commonly encountered types of data, usually around 2/3rd’s of the values are within one standard deviation of the range.

Question 12

the median can never be more than______ from the average.

Answer 12

one standard deviation away from the average.

Question 13

Adding a constant amount to all data values does what to the SD?

Answer 13

does not change the SD

Question 14

Multiplying all data values by the same positive constant amount does what to the SD and average?

Answer 14

multiplies the standard deviation and average by that same amount.