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Finding the Fourth Proportional to 813.47, 1,220.15 and 265.57

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Solution

The fourth proportional to 813.47, 1,220.15 and 265.57 is: 398.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.47 : 1,220.15 = 265.57 : x
  2. Step 2: Convert to fraction form
    813.47/1,220.15 = 265.57/x
  3. Step 3: Cross multiply
    813.47x = 1,220.15 × 265.57
  4. Step 4: Simplify right side
    813.47x = 324,032.85
  5. Step 5: Solve for x
    x = 324,032.85/813.47
  6. Step 6: Final answer
    x = 398.34

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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.