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Finding the Third Proportional to 431.50 and 515.50

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Solution

The third proportional to 431.50 and 515.50 is: 615.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.50 : 515.50 = 515.50 : x
  2. Step 2: Convert to fraction form
    431.50/515.50 = 515.50/x
  3. Step 3: Cross multiply
    431.50x = 515.50 × 515.50
  4. Step 4: Simplify right side
    431.50x = 265,740.25
  5. Step 5: Solve for x
    x = 265,740.25/431.50
  6. Step 6: Final answer
    x = 615.85

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Why These Related Problems?

These problems maintain the same ratio (1.19) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.