Write the following proportion using colons: 7 is to 21 as 3 is to 9.
A) [tex]$7: 21=3: 9$[/tex]
B) [tex]$21: 7=3: 9$[/tex]
C) [tex]$7: 3=21: 9$[/tex]
D) [tex]$7: 21=9: 3$[/tex]
Answer (1)
The problem requires expressing the proportion '7 is to 21 as 3 is to 9' using colons. The ratio 7:21 represents '7 is to 21', and the ratio 3:9 represents '3 is to 9'. The proportion is then written as 7:21 = 3:9. The final answer is \boxed{7: 21=3: 9}.
Explanation
Understanding the Proportion We need to express the proportion '7 is to 21 as 3 is to 9' using colons. This means we need to represent the ratios 7:21 and 3:9 and equate them.
Expressing Ratios The proportion '7 is to 21' can be written as the ratio 7:21. Similarly, '3 is to 9' can be written as 3:9.
Forming the Proportion Combining these, the proportion '7 is to 21 as 3 is to 9' is written as 7:21 = 3:9.
Examples
Proportions are used in everyday life to scale recipes, convert units, and understand maps. For example, if a map has a scale of 1 inch to 10 miles, the proportion helps you determine the actual distance between two locations on the map. Understanding proportions allows for accurate scaling and conversions in various real-world scenarios, ensuring that relationships between quantities are maintained.
