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Finding the Fourth Proportional to 678.58, 1,017.41 and 418.57

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Solution

The fourth proportional to 678.58, 1,017.41 and 418.57 is: 627.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.58 : 1,017.41 = 418.57 : x
  2. Step 2: Convert to fraction form
    678.58/1,017.41 = 418.57/x
  3. Step 3: Cross multiply
    678.58x = 1,017.41 × 418.57
  4. Step 4: Simplify right side
    678.58x = 425,855.02
  5. Step 5: Solve for x
    x = 425,855.02/678.58
  6. Step 6: Final answer
    x = 627.57

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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.