The time-series graph below gives the price (USD) of a gallon of gas each month over the course of a year. Find the time intervals during which gas prices are increasing.
 

• A. Jan-Feb and Jun-Aug
• B. Feb-Dec
• C. Mar-Apr and May-Jun
• D. Feb-Jun and Aug-Dec

Answer: (D)

Verified step by step guidance

1. Step 1: Observe the time-series graph provided. The x-axis represents months from January to December, and the y-axis represents the price of gas in USD.
2. Step 2: Identify the intervals where the graph shows an upward trend, indicating an increase in gas prices. Look for sections where the line connecting the points slopes upward.
3. Step 3: From February to June, the graph shows a consistent upward trend, as the price increases from approximately \$2.98 in February to \$3.12 in June.
4. Step 4: From August to December, the graph again shows an upward trend, as the price increases from approximately \$3.02 in August to \$3.12 in December.
5. Step 5: Combine the identified intervals to conclude that the gas prices are increasing during the time intervals February to June and August to December.