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Finding the Fourth Proportional to 688.12, 1,031.36 and 322.20

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Solution

The fourth proportional to 688.12, 1,031.36 and 322.20 is: 482.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.12 : 1,031.36 = 322.20 : x
  2. Step 2: Convert to fraction form
    688.12/1,031.36 = 322.20/x
  3. Step 3: Cross multiply
    688.12x = 1,031.36 × 322.20
  4. Step 4: Simplify right side
    688.12x = 332,302.58
  5. Step 5: Solve for x
    x = 332,302.58/688.12
  6. Step 6: Final answer
    x = 482.92

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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.