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Finding the Fourth Proportional to 808.85, 1,213.36 and 260.90

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Solution

The fourth proportional to 808.85, 1,213.36 and 260.90 is: 391.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.85 : 1,213.36 = 260.90 : x
  2. Step 2: Convert to fraction form
    808.85/1,213.36 = 260.90/x
  3. Step 3: Cross multiply
    808.85x = 1,213.36 × 260.90
  4. Step 4: Simplify right side
    808.85x = 316,565.62
  5. Step 5: Solve for x
    x = 316,565.62/808.85
  6. Step 6: Final answer
    x = 391.38

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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.