Please help not understanding this question.
If the cost of a cell phone has decreased 400% during the past 10 years, does that correspond to a cost decrease of four times? Make up your own numbers in an example and then explain your answer as though you were talking to someone who has never taken algebra
Sure! Let's use an example to explain this. Let's say the original cost of a cell phone 10 years ago was $100.
To determine the decrease in cost, we need to calculate 400% of the original cost, which means multiplying the original cost by 400% (or 4 in decimal form).
400% of $100 = 4 * $100 = $400
So, based on this example, the calculated decrease in cost is $400.
Now, let's consider the question of whether this corresponds to a cost decrease of four times. To clarify this, we need to understand what is meant by "four times."
If we wanted to decrease the cost by four times, we could multiply the original cost by 4:
$100 * 4 = $400
In this case, the decreased cost of $400 is indeed four times the original cost of $100.
However, in the original question, it states that the cost has decreased by 400%. This means that the new cost is only 100% - 400% = -300% of the original cost. The negative sign indicates a decrease.
To find the new decreased cost, we can calculate -300% of $100:
-300% of $100 = (-3 * $100) = -$300
As you can see, the new decreased cost is -$300. This means the cell phone's cost has decreased by $300 from the original price of $100.
Therefore, the cost decrease of four times and the cost decrease of 400% are not the same. The 400% decrease corresponds to a decrease of -$300, whereas a cost decrease of four times corresponds to a decrease of -$400.