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Finding the Fourth Proportional to 685.78, 945.66 and 518.13

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Solution

The fourth proportional to 685.78, 945.66 and 518.13 is: 714.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.78 : 945.66 = 518.13 : x
  2. Step 2: Convert to fraction form
    685.78/945.66 = 518.13/x
  3. Step 3: Cross multiply
    685.78x = 945.66 × 518.13
  4. Step 4: Simplify right side
    685.78x = 489,976.76
  5. Step 5: Solve for x
    x = 489,976.76/685.78
  6. Step 6: Final answer
    x = 714.48

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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.