Midterm Exam Quiz- Business Statistics

A population is

• a planned activity whose results yield a set of data

• consists of all the items or individuals about which you want to reach conclusions.

• the set of values collected from the variable from each of the elements that belong to the sample

• A numerical value summarizing the sample data

A sample is

• a subset of a population

• an infinite selection of a population

• a characteristic of a population

• a data value generated by the statistical information

Parameters are used to describe

• sample

• population

• value

• data

A statistic is

• a planned activity whose results yield a set of data

• a numerical value that summarizes all of the data of an entire population

• the set of values collected from the variable

• A numerical value summarizing the sample data

Which is the characteristic of systematic sample

• every item from a frame has the same chance of selection as every other item

• expensive to implement

• divide the N items in the frame into clusters that contain several

  items

• taking every kth item from the entire frame

Which one is a discrete variable

• Number of cellphones in the household

• Monthly data usage (in MB)

• Voice usage per month (in minutes)

• Whether the cellphone is used for email

Find the MEDIAN

77, 83, 83, 85, 87, 90, 90, 93, 94, 99, 99

• 85

• 87

• 90

• 93

Variation is

• the extent to which the values of a numerical variable group around a typical, or central, value.

• the amount of dispersion, or scattering, away from a central value that the values of a numerical variable show

• the pattern of the distribution of values from the lowest value to the highest value.

• Describing the relationship between two numerical variables

Joint event is

• each possible outcome of a variable

• collection of all the possible events

• described by a single characteristic

• an event that has two or more characteristics

What one is NOT right about Z-score

• Z scores help identify outliers

• The Z score of a value is the difference between that value and the mean, divided by the standard deviation

• Z-score can not be negative

• Z-score can be zero