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Finding the Third Proportional to 315,840 and 690,720

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Solution

The third proportional to 315,840 and 690,720 is: 1,510,556.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    315,840 : 690,720 = 690,720 : x
  2. Step 2: Convert to fraction form
    315,840/690,720 = 690,720/x
  3. Step 3: Cross multiply
    315,840x = 690,720 × 690,720
  4. Step 4: Simplify right side
    315,840x = 477,094,118,400
  5. Step 5: Solve for x
    x = 477,094,118,400/315,840
  6. Step 6: Final answer
    x = 1,510,556.35

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Why These Related Problems?

These problems maintain the same ratio (2.19) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.