MC: Central Tendency

Question 1

If variables have 0 correlation it means there is no ________.

Answer 1

Linear relationship but there could be another .

Question 2

What are 3 causes for spurious correlation?

Answer 2

1. Noise
2. Some third variable
3. Mathematical change done by observer

Question 3

What is the equation for correlation?

Answer 3

Covariance divided by the product of the standard deviation of both variables.

Question 4

What is the formula for excess kurtosis?

Answer 4

= Kurtosis - 3

Question 5

Describe discrete data

Answer 5

Shoe size. Finite buckets for measure.

Question 6

Describe continuous data.

Answer 6

Inches or cm measurement.
Could be 1.5, 1.757, .790

Question 7

75% of the data points are less than the ______.

Answer 7

Third quartile

Question 8

What is the interquartile range?

Answer 8

75% - 25% of observations.
1st & 3rd Quartile.

Question 9

To display outlier values on a box and whisker plot, what can be done?

Answer 9

Fences can be built 1.5x the interquartile range, instead of at the highest and lowest points.

Question 10

Sample variance you divide the sum by ______.

Answer 10

N-1

Question 11

When using target standard deviation, does the n in “n-1” include only outcomes in target?

Answer 11

No. All are included.

Question 12

Skewness is based on the average _____ deviation from the mean.

Answer 12

Cubed

Question 13

Peakness of a distribution is measured by ________.

Answer 13

Kurtosis

Question 14

Kurtosis is based on the average _____ deviation from the mean.

Answer 14

Forth powered