Finding the Third Proportional to 405 and 990
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Solution
The third proportional to 405 and 990 is: 2,420
Step by Step Solution
- Step 1: Write the proportion equation
405 : 990 = 990 : x - Step 2: Convert to fraction form
405/990 = 990/x - Step 3: Cross multiply
405x = 990 × 990 - Step 4: Simplify right side
405x = 980,100 - Step 5: Solve for x
x = 980,100/405 - Step 6: Final answer
x = 2,420
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Why These Related Problems?
These problems maintain the same ratio (2.44) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.