Question

the bar graph shows monthly electric bill costs with and without solar panels. which conclusion is best supported by the data? solar panels always work. solar panels cut the july electric bill in half. solar panels are not cost - effective every month. solar panels are not as cost - effective in winter as they are at other times of year.

Explanation:

Looking at the bar graph, we can see that in some months (e.g., July), the cost with solar panels is much lower than without. But in other months (e.g., December), the cost - saving is not as significant. This shows that solar panels do not provide the same level of cost - effectiveness across all months.

• "Solar panels always work" is too absolute. Just because they reduce cost in some months doesn't mean they "always work" in an undefined sense (the graph is about cost, not functionality).
• For "Solar panels cut the July electric bill in half", we don't have exact numerical values to confirm a "half" cut from the description.
• "Solar panels are not as cost - effective in winter as they are at other times of year" is not supported as we don't know which months are winter months from the given information.

Answer:

Solar panels are not cost - effective every month.