Data Summary

Question 1

What is Quantitative data?

Answer 1

Data measuring some quantity resulting in a numerical value

Question 2

What is Qualitative data?

Answer 2

Data measuring the quality of something resulting in a value that doesn’t have a numerical value (colour, religion, seasons)

Question 3

What is discrete quantitive data?

Answer 3

Data with distinct values and possible values take only a distinct series of numbers (number of traffic accidents, number of children born to a women)

Question 4

What is continuous quantitive data?

Answer 4

Data with a value that can be measured evermore precisely (heights, speed)

Question 5

What is ordinal qualitative data?

Answer 5

Non-numerical value but values that have some natural order (poor, fair, good, great)

Question 6

What is nominal qualitative data?

Answer 6

Unordered, distinct by name only (red, blue, green)

Question 7

What is a frequency distribution?

Answer 7

Used for discrete variables, with a limited number of distinct values. Formed by counting the number of frequency of each distinct value.

Question 8

Meaning: mode

Answer 8

Most frequently recorded value

Question 9

What re some measures of centre?

Answer 9

Mean and median

Question 10

What are some measures of spread?

Answer 10

Range, interquartile range, sample variance, standard deviation

Question 11

Why do we not usually know the population mean parameter?

Answer 11

Would have to sample the whole population which takes too long/ is too expensive

Question 12

What would you use if you didn’t know the true value of the parameter?

Answer 12

Obtain the estimate (mu hat), the sample mean.

Question 13

How would you find the sample mean (mu hat)?

Answer 13

Mu hat = the average of the set of values being used divided by the sample size

Question 14

How would you find an outcome?

Answer 14

Outcome = (mean) + error

Question 15

How would you find the destiny at some i?

Answer 15

Destiny at some time/location i is equal to the mean destiny plus some error

Question 16

How would you find the sample median?

Answer 16

Sort the values into value order and find the middle number

Question 17

What is the calculation for find the sample median for an ordered set of values?

Answer 17

(n+1)/2

Question 18

What is the range?

Answer 18

The difference between the max and min value

Question 19

What is an outlier?

Answer 19

A value that is very different to the other values

Question 20

How do you find the interquartile range?

Answer 20

The 75th percentile minus the 25th percentile, and 50% of the data lies in that range

Question 21

What is the error useful for?

Answer 21

The size of the error determines whether the model is a good or bad fit for the data

Question 22

When would you use a bar plot?

Answer 22

When illustrating frequency information across discrete categories or groups

Question 23

When would you use a histogram?

Answer 23

Used to display continuous data, data portioned into distinct bins

Question 24

If he tail of the histogram is on the left what way is it skewed?

Answer 24

Left skewed

Question 25

If the mean is less than the median what way is the graph skewed?

Answer 25

Left

Question 26

When would you use a box plot?

Answer 26

Used to convey summary information about a variable

Question 27

What do notched box plots include?

Answer 27

Info about the median

Question 28

What are violin plots a combination of?

Answer 28

Box plots and a smoothed sideways histogram

Question 29

What do the x and y variables usually represent?

Answer 29

X - explanatory variable

Y - response variable

Question 30

Why would a scatter plot be used?

Answer 30

If there are two continuous variables