Problem 34 - Beginning and Intermediate Algebra

Question

Use a signed number to express each number in boldface italics. On Wednesday, November \(8,2017,\) the NASDAQ closed at \(6789.12 .\) On the previous day, it had closed at 6767.78 . Thus, on Wednesday, it closed up 21.34 points. (Data from Wall Street Joumal.)

Step-by-Step Solution

Answer

+21.34

Step 1: Identify Previous Closing Value

The NASDAQ closed at 6767.78 on the previous day.

Step 2: Identify Current Closing Value

The NASDAQ closed at 6789.12 on Wednesday.

Step 3: Determine the Change in Points

To find the change in points, subtract the previous closing value from the current closing value: 6789.12 - 6767.78 = 21.34

Step 4: Express the Change with a Signed Number

Since the NASDAQ closed up by 21.34 points, this can be expressed as a positive signed number: +21.34

Key Concepts

NASDAQ closing values

When discussing the NASDAQ, the 'closing value' is essential. It represents the final price at which all stocks on this index were traded at the end of a trading day. For instance, on Wednesday, November 8, 2017, the NASDAQ closed at 6789.12. The day before, it closed at 6767.78. These numbers provide investors with valuable information about market trends.
Keeping track of closing values helps to understand whether the market is generally gaining or losing value over time. In finance, these values dictate decision-making processes based on their rise or fall.

points change calculation

Calculating the change in points is a fundamental skill in financial mathematics. This involves simple subtraction to determine the difference between two values. Let's use our example:

Previous closing value: 6767.78
Current closing value: 6789.12

To find the change, we subtract the previous value from the current value:

6789.12 - 6767.78 = 21.34

This change tells us how much the NASDAQ increased or decreased on a given day. Being up by 21.34 points tells investors that the index gained value, which is usually a positive sign for those who have investments in that market.

positive and negative numbers in algebra

In algebra, signed numbers are used to represent both positive and negative values. This is incredibly useful in various fields, including finance. When we say 'signed numbers,' we mean numbers that have either a positive (+) or negative (-) sign in front of them.

For example, if the NASDAQ rises by 21.34 points, we write this as +21.34. Conversely, if it had fallen, we would write this as -21.34. This notation helps to quickly understand the direction of change.

Here are some key points to remember about signed numbers:

• Positive numbers indicate a gain or increase.
• Negative numbers indicate a loss or decrease.
• When performing calculations, always pay attention to the signs.

Understanding how to use signed numbers is crucial, especially when interpreting changes in financial data like the NASDAQ closing values.