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Finding the Fourth Proportional to 865.85, 1,298.43 and 378.56

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Solution

The fourth proportional to 865.85, 1,298.43 and 378.56 is: 567.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.85 : 1,298.43 = 378.56 : x
  2. Step 2: Convert to fraction form
    865.85/1,298.43 = 378.56/x
  3. Step 3: Cross multiply
    865.85x = 1,298.43 × 378.56
  4. Step 4: Simplify right side
    865.85x = 491,533.66
  5. Step 5: Solve for x
    x = 491,533.66/865.85
  6. Step 6: Final answer
    x = 567.69

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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.