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Finding the Fourth Proportional to 345.78, 478.14 and 331.32

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Solution

The fourth proportional to 345.78, 478.14 and 331.32 is: 458.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    345.78 : 478.14 = 331.32 : x
  2. Step 2: Convert to fraction form
    345.78/478.14 = 331.32/x
  3. Step 3: Cross multiply
    345.78x = 478.14 × 331.32
  4. Step 4: Simplify right side
    345.78x = 158,417.34
  5. Step 5: Solve for x
    x = 158,417.34/345.78
  6. Step 6: Final answer
    x = 458.14

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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.