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Finding the Fourth Proportional to 721.68, 1,076.34 and 618

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Solution

The fourth proportional to 721.68, 1,076.34 and 618 is: 921.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.68 : 1,076.34 = 618 : x
  2. Step 2: Convert to fraction form
    721.68/1,076.34 = 618/x
  3. Step 3: Cross multiply
    721.68x = 1,076.34 × 618
  4. Step 4: Simplify right side
    721.68x = 665,178.12
  5. Step 5: Solve for x
    x = 665,178.12/721.68
  6. Step 6: Final answer
    x = 921.71

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.