Reading 10: Sampling and Estimation - LOS c ～ Q1-2

答案和详解如下：

1.The sample of per square foot sales for 100 U.S. retailers in December 2004 is an example of:

A)   cross-sectional data.

B)   unbiased data.

C)   time-series data.

D)   randomly-distributed data.

The correct answer was A)

Cross-sectional data are a sample of observations taken at a single point in time. A time-series is a sample of observations taken at specific and equally spaced points in time.

2.Monthly Gross Domestic Product (GDP) figures from 1990-2000 are an example of:

A)   systematic data.

B)   non-random data.

C)   cross-sectional data.

D)   time-series data.

The correct answer was D)

A time-series is a group of observations taken at specific and equally spaced points in time. Cross-sectional data are observations taken at a single point in time.