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Finding the Fourth Proportional to 688.68, 1,031.37 and 399.24

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Solution

The fourth proportional to 688.68, 1,031.37 and 399.24 is: 597.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.68 : 1,031.37 = 399.24 : x
  2. Step 2: Convert to fraction form
    688.68/1,031.37 = 399.24/x
  3. Step 3: Cross multiply
    688.68x = 1,031.37 × 399.24
  4. Step 4: Simplify right side
    688.68x = 411,764.16
  5. Step 5: Solve for x
    x = 411,764.16/688.68
  6. Step 6: Final answer
    x = 597.90

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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.