Question

A major bank collected data on​ 100,000 of its customers​(income, sex,​ location, number of​ cards, etc.) and then computed how much profit it made from the account of these customers during the past calendar year. Let the variables​ "Income," "Sex,"​"Location," "Cards," and​ "Profit" record the​ income, sex,​location, number of​ cards, and​ profit, respectively, for the customers.

​(a) Identify whether the data are cross-sectional or a time series.

​(b) Indicate if each variable is​ categorical, ordinal, or numerical​ (If a variable is​ numerical, include its units if​possible).

​(c) List any concerns that you might have for the accuracy of the data.

Answer 1

(a)

The data are cross - sectional because it is an observational study that analyses data from a population at a specific point in time,here during the past calendar year.

(b)

Variable	Type of variable
Income	numerical. units: dollars
Sex	Categorical
Location	Categorical
Number of cards	numerical. units: Nil (pure number)
Profit	numerical. units: dollars

(c)

Since the data pertains to entire past calendar year, many of the data items like Income, Location, Number of cards etc., will be changing from time to time for each customer and since the data set is quite large, accounting such variations will give inaccurate data.