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Finding the Fourth Proportional to 608.78, 839.87 and 387.86

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Solution

The fourth proportional to 608.78, 839.87 and 387.86 is: 535.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    608.78 : 839.87 = 387.86 : x
  2. Step 2: Convert to fraction form
    608.78/839.87 = 387.86/x
  3. Step 3: Cross multiply
    608.78x = 839.87 × 387.86
  4. Step 4: Simplify right side
    608.78x = 325,747.29
  5. Step 5: Solve for x
    x = 325,747.29/608.78
  6. Step 6: Final answer
    x = 535.08

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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.