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Finding the Fourth Proportional to 318.61, 478.12 and 284.78

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Solution

The fourth proportional to 318.61, 478.12 and 284.78 is: 427.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.61 : 478.12 = 284.78 : x
  2. Step 2: Convert to fraction form
    318.61/478.12 = 284.78/x
  3. Step 3: Cross multiply
    318.61x = 478.12 × 284.78
  4. Step 4: Simplify right side
    318.61x = 136,159.01
  5. Step 5: Solve for x
    x = 136,159.01/318.61
  6. Step 6: Final answer
    x = 427.35

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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.