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Finding the Fourth Proportional to 687.36, 1,031.19 and 340.88

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Solution

The fourth proportional to 687.36, 1,031.19 and 340.88 is: 511.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.36 : 1,031.19 = 340.88 : x
  2. Step 2: Convert to fraction form
    687.36/1,031.19 = 340.88/x
  3. Step 3: Cross multiply
    687.36x = 1,031.19 × 340.88
  4. Step 4: Simplify right side
    687.36x = 351,509.48
  5. Step 5: Solve for x
    x = 351,509.48/687.36
  6. Step 6: Final answer
    x = 511.39

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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.