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Finding the Fourth Proportional to 681.64, 940.64 and 386.88

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Solution

The fourth proportional to 681.64, 940.64 and 386.88 is: 533.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.64 : 940.64 = 386.88 : x
  2. Step 2: Convert to fraction form
    681.64/940.64 = 386.88/x
  3. Step 3: Cross multiply
    681.64x = 940.64 × 386.88
  4. Step 4: Simplify right side
    681.64x = 363,910.43
  5. Step 5: Solve for x
    x = 363,910.43/681.64
  6. Step 6: Final answer
    x = 533.87

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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.