Ch2 Measures of location and spread

Question 1

mean

Answer 1

sum of values/ number of values

Question 2

mean from frequency table

Answer 2

sum of (values x frequency) / sum of frequency

Question 3

Quartiles

Answer 3

lower quartile = n/4

median = n/2

upper quartile = 3/4 n

Question 4

Finding a value using interpolation

Answer 4

beginning of category
+
(value number - prior frequency / category frequency)
x
Category difference

Question 5

standard deviation

Answer 5

square root of( (sum of x^2/n) - (sum of x/n)^2)