Is Arecibo on steady ground?

What it is: This is the price homes pay for power. Power is sold by the kilowatt-hour, and this is the price in cents for each one.

Why it moves: Many power plants burn fuel, like natural gas, to make power. When that fuel costs more, power costs more. New power lines and plants add to the price over time. Hot summers and cold winters make people use more.

Who controls it: In many states, a state board must say yes to what power companies charge homes. In some states, homes can pick who they buy power from. Buyers and sellers set fuel prices.

What it means for you: When it goes up, the same power use costs you more each month.

What it is: This is the price of a gallon of regular gas at the pump.

Why it moves: Gas is made from oil, so when oil costs more, gas costs more. Prices often rise in summer, when more people drive. They can jump when a plant that makes gas shuts down. Taxes are part of the price too.

Who controls it: Buyers and sellers around the world set the price of oil. Some countries that pump a lot of oil agree on how much to pump. Each gas station sets its own price.

What it means for you: When it goes up, it costs more to fill your tank and get where you need to go.

What it is: This shows how much the prices of food from stores have changed in a year. It is food you buy to eat at home, not meals out.

Why it moves: Food costs more when it costs more to grow, pack and ship. Bad weather or sick animals can mean less food to sell, and prices go up. Fuel and workers' pay are part of the cost too.

Who controls it: Stores set their own prices. They follow what farms, food makers and shippers charge them. No one group sets food prices.

What it means for you: When it goes up, the same cart of groceries costs more. That leaves less money for other things.