Unit 5

Question 1

provides a compact way of writing statistical formulas.

Answer 1

summation notation

Question 2

the mathematical symbol used to denote the sum of numerical values

Answer 2

capital Greek letter sigma, Σ

Question 3

any single value that is used to identify the “center” or the typical value of a data set. It provides a summary of the data which facilitates comparison of two or more data sets. It is often referred to as the average

Answer 3

measures of central tendency

Question 4

commonly used measures of central tendency

Answer 4

arithmetic mean, median, and mode

Question 5

characteristics of a good average

Answer 5

• easily understood
• objective and rigidly defined
• stable

Question 6

sum of all values of the observations divided by the number of observations

Answer 6

arithmetic mean

Question 7

a modification of the usual mean that assigns weights (or
measures of relative importance) to the observations to be averaged.

Answer 7

weighted mean

Question 8

if k finite populations having 𝑁1, 𝑁2, … , 𝑁𝑘, respectively, have means 𝜇1, 𝜇2, … , 𝜇𝑘. Then the combined population mean 𝜇𝑐

Answer 8

combined mean

Question 9

a α%-trimmed mean can be used to mitigate the effects of outliers. To find the α%-trimmed mean of a data set, order the data, delete the lowest α% and the highest α% of these observations, and find the arithmetic mean of the remaining entries

Answer 9

trimmed mean

Question 10

the value that divides that array into two equal parts If the number
of observations

Answer 10

median

Question 11

the observed value that occurs most frequently in a data set

Answer 11

mode