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Finding the Fourth Proportional to 385.62, 530.91 and 312.18

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Solution

The fourth proportional to 385.62, 530.91 and 312.18 is: 429.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.62 : 530.91 = 312.18 : x
  2. Step 2: Convert to fraction form
    385.62/530.91 = 312.18/x
  3. Step 3: Cross multiply
    385.62x = 530.91 × 312.18
  4. Step 4: Simplify right side
    385.62x = 165,739.48
  5. Step 5: Solve for x
    x = 165,739.48/385.62
  6. Step 6: Final answer
    x = 429.80

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.