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Finding the Fourth Proportional to 346.78, 478.42 and 308.91

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Solution

The fourth proportional to 346.78, 478.42 and 308.91 is: 426.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    346.78 : 478.42 = 308.91 : x
  2. Step 2: Convert to fraction form
    346.78/478.42 = 308.91/x
  3. Step 3: Cross multiply
    346.78x = 478.42 × 308.91
  4. Step 4: Simplify right side
    346.78x = 147,789.11
  5. Step 5: Solve for x
    x = 147,789.11/346.78
  6. Step 6: Final answer
    x = 426.17

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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.