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Finding the Fourth Proportional to 609.80, 914.70 and 391.10

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Solution

The fourth proportional to 609.80, 914.70 and 391.10 is: 586.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    609.80 : 914.70 = 391.10 : x
  2. Step 2: Convert to fraction form
    609.80/914.70 = 391.10/x
  3. Step 3: Cross multiply
    609.80x = 914.70 × 391.10
  4. Step 4: Simplify right side
    609.80x = 357,739.17
  5. Step 5: Solve for x
    x = 357,739.17/609.80
  6. Step 6: Final answer
    x = 586.65

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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.