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Finding the Fourth Proportional to 678.87, 1,018.71 and 268.20

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Solution

The fourth proportional to 678.87, 1,018.71 and 268.20 is: 402.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.87 : 1,018.71 = 268.20 : x
  2. Step 2: Convert to fraction form
    678.87/1,018.71 = 268.20/x
  3. Step 3: Cross multiply
    678.87x = 1,018.71 × 268.20
  4. Step 4: Simplify right side
    678.87x = 273,218.02
  5. Step 5: Solve for x
    x = 273,218.02/678.87
  6. Step 6: Final answer
    x = 402.46

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.