Question content area top

Part 1
The stock market report says that 7 stocks went up for every 8 stocks that went down. If 960 stocks went down​ yesterday, how many went​ up? Set up and solve a proportion for the problem.

1 answer

To solve the problem, we first need to set up a proportion based on the information provided.

We know that for every 7 stocks that went up, 8 stocks went down. The relationship can be expressed as:

\[ \frac{\text{Stocks Up}}{\text{Stocks Down}} = \frac{7}{8} \]

Let \( x \) be the number of stocks that went up. According to the problem, we know that 960 stocks went down. We can set up the proportion as follows:

\[ \frac{x}{960} = \frac{7}{8} \]

Now, we can solve for \( x \) by cross-multiplying:

\[ 8x = 7 \times 960 \]

Calculating the right side gives:

\[ 7 \times 960 = 6720 \]

So we have:

\[ 8x = 6720 \]

Now, divide both sides by 8 to solve for \( x \):

\[ x = \frac{6720}{8} = 840 \]

Thus, the number of stocks that went up is \( \boxed{840} \).