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Finding the Fourth Proportional to 813.46, 1,220.20 and 265.70

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Solution

The fourth proportional to 813.46, 1,220.20 and 265.70 is: 398.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.46 : 1,220.20 = 265.70 : x
  2. Step 2: Convert to fraction form
    813.46/1,220.20 = 265.70/x
  3. Step 3: Cross multiply
    813.46x = 1,220.20 × 265.70
  4. Step 4: Simplify right side
    813.46x = 324,207.14
  5. Step 5: Solve for x
    x = 324,207.14/813.46
  6. Step 6: Final answer
    x = 398.55

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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.