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Finding the Fourth Proportional to 681.76, 940.78 and 387.06

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Solution

The fourth proportional to 681.76, 940.78 and 387.06 is: 534.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.76 : 940.78 = 387.06 : x
  2. Step 2: Convert to fraction form
    681.76/940.78 = 387.06/x
  3. Step 3: Cross multiply
    681.76x = 940.78 × 387.06
  4. Step 4: Simplify right side
    681.76x = 364,138.31
  5. Step 5: Solve for x
    x = 364,138.31/681.76
  6. Step 6: Final answer
    x = 534.12

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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.