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Finding the Fourth Proportional to 678.45, 1,017.87 and 354.03

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Solution

The fourth proportional to 678.45, 1,017.87 and 354.03 is: 531.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.45 : 1,017.87 = 354.03 : x
  2. Step 2: Convert to fraction form
    678.45/1,017.87 = 354.03/x
  3. Step 3: Cross multiply
    678.45x = 1,017.87 × 354.03
  4. Step 4: Simplify right side
    678.45x = 360,356.52
  5. Step 5: Solve for x
    x = 360,356.52/678.45
  6. Step 6: Final answer
    x = 531.15

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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.