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Finding the Fourth Proportional to 512.70, 707.72 and 505.20

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Solution

The fourth proportional to 512.70, 707.72 and 505.20 is: 697.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    512.70 : 707.72 = 505.20 : x
  2. Step 2: Convert to fraction form
    512.70/707.72 = 505.20/x
  3. Step 3: Cross multiply
    512.70x = 707.72 × 505.20
  4. Step 4: Simplify right side
    512.70x = 357,540.14
  5. Step 5: Solve for x
    x = 357,540.14/512.70
  6. Step 6: Final answer
    x = 697.37

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.