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Finding the Fourth Proportional to 687.07, 1,029.69 and 339.88

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Solution

The fourth proportional to 687.07, 1,029.69 and 339.88 is: 509.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.07 : 1,029.69 = 339.88 : x
  2. Step 2: Convert to fraction form
    687.07/1,029.69 = 339.88/x
  3. Step 3: Cross multiply
    687.07x = 1,029.69 × 339.88
  4. Step 4: Simplify right side
    687.07x = 349,971.04
  5. Step 5: Solve for x
    x = 349,971.04/687.07
  6. Step 6: Final answer
    x = 509.37

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.