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Finding the Fourth Proportional to 678.12, 1,017.45 and 634.38

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Solution

The fourth proportional to 678.12, 1,017.45 and 634.38 is: 951.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.12 : 1,017.45 = 634.38 : x
  2. Step 2: Convert to fraction form
    678.12/1,017.45 = 634.38/x
  3. Step 3: Cross multiply
    678.12x = 1,017.45 × 634.38
  4. Step 4: Simplify right side
    678.12x = 645,449.93
  5. Step 5: Solve for x
    x = 645,449.93/678.12
  6. Step 6: Final answer
    x = 951.82

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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.