Macroeconomics is a field of economics which concerns performance, structure, behavior, and decisions of an economy at aggregate levels. There are three key issues in macroeconomics, e.g. output growth, price level and employment. Finish the questions of macroeconomic concepts and issues as following.

(1) Consumer Price Index (CPI) is a price indicator to reflect price levels over time. As a key economic indicator, CPI is computed monthly by the Bureau of Labor Statistics (BLS) using a "market basket" purchased by the typical consumer each month. Suppose you are doing a study to yearly price levels (CPI) of a metropolitan area in the US. Its CPI includes three categories, Food (grocery), Energy (gasoline) and other items (all goods and services less food and energy). The table below provides you the prices of the three categories in 2019, 2020 and 2021. Also, you have the units purchased by a typical consumer in these three categories. Use 2019 as the base year,to show step-by-step solutions for CPI in 2019, 2020 and 2021.

Prices ($) and Units of selected Categories of CPI

Item	Unit	2019 ($)	2020 ($)	2021 ($)
Food	10	6.00	5.50	6.75
Energy	5	2.50	1.80	2.90
Other items	25	20.00	19.00	22.50

(2) Being another key indicator, employment reflects the current status of an economy. Empirical evidence shows a higher growth rate of national output (GDP) usually goes hand-in-hand with a lower unemployment rate. In a study to the economic impact of the Covid-19 pandemics in the US, you noticed that during the pandemics, unemployment rises across states in 2020. Similarly, after state economies reopened and moved quickly out of the Covid-19 recession, unemployment rates also dropped in most states. However, there are still noticeable regional differences of how the job market performed in different states. The table below compares unemployment rates of Arkansas, California, New York and Texas in October 2019 (10/2019), October 2020 (10/2020) and October 2021 (10/2021). Use your language to explain the differences of unemployment rate between Arkansas and other three states.

Unemployment rate (%) of selected States

Date	Arkansas	California	New York	Texas
10/2019	3.5	3.9	3.9	3.5
10/2020	5.6	9.8	8.7	7.3
10/2021	3.7	7.3	6.9	5.4