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Finding the Fourth Proportional to 814.68, 1,220.40 and 505.80

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Solution

The fourth proportional to 814.68, 1,220.40 and 505.80 is: 757.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.68 : 1,220.40 = 505.80 : x
  2. Step 2: Convert to fraction form
    814.68/1,220.40 = 505.80/x
  3. Step 3: Cross multiply
    814.68x = 1,220.40 × 505.80
  4. Step 4: Simplify right side
    814.68x = 617,278.32
  5. Step 5: Solve for x
    x = 617,278.32/814.68
  6. Step 6: Final answer
    x = 757.69

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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.