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Finding the Fourth Proportional to 509.78, 699.27 and 505.39

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Solution

The fourth proportional to 509.78, 699.27 and 505.39 is: 693.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.78 : 699.27 = 505.39 : x
  2. Step 2: Convert to fraction form
    509.78/699.27 = 505.39/x
  3. Step 3: Cross multiply
    509.78x = 699.27 × 505.39
  4. Step 4: Simplify right side
    509.78x = 353,404.07
  5. Step 5: Solve for x
    x = 353,404.07/509.78
  6. Step 6: Final answer
    x = 693.25

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.