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Finding the Fourth Proportional to 813.79, 1,218.03 and 505.90

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Solution

The fourth proportional to 813.79, 1,218.03 and 505.90 is: 757.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.79 : 1,218.03 = 505.90 : x
  2. Step 2: Convert to fraction form
    813.79/1,218.03 = 505.90/x
  3. Step 3: Cross multiply
    813.79x = 1,218.03 × 505.90
  4. Step 4: Simplify right side
    813.79x = 616,201.38
  5. Step 5: Solve for x
    x = 616,201.38/813.79
  6. Step 6: Final answer
    x = 757.20

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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.