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Finding the Fourth Proportional to 978.87, 1,350.46 and 624.80

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Solution

The fourth proportional to 978.87, 1,350.46 and 624.80 is: 861.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    978.87 : 1,350.46 = 624.80 : x
  2. Step 2: Convert to fraction form
    978.87/1,350.46 = 624.80/x
  3. Step 3: Cross multiply
    978.87x = 1,350.46 × 624.80
  4. Step 4: Simplify right side
    978.87x = 843,771.42
  5. Step 5: Solve for x
    x = 843,771.42/978.87
  6. Step 6: Final answer
    x = 861.99

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.