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Finding the Fourth Proportional to 714.78, 987.23 and 478.34

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Solution

The fourth proportional to 714.78, 987.23 and 478.34 is: 660.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    714.78 : 987.23 = 478.34 : x
  2. Step 2: Convert to fraction form
    714.78/987.23 = 478.34/x
  3. Step 3: Cross multiply
    714.78x = 987.23 × 478.34
  4. Step 4: Simplify right side
    714.78x = 472,224.27
  5. Step 5: Solve for x
    x = 472,224.27/714.78
  6. Step 6: Final answer
    x = 660.66

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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.