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Finding the Fourth Proportional to 840.70, 1,261.86 and 379

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Solution

The fourth proportional to 840.70, 1,261.86 and 379 is: 568.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.70 : 1,261.86 = 379 : x
  2. Step 2: Convert to fraction form
    840.70/1,261.86 = 379/x
  3. Step 3: Cross multiply
    840.70x = 1,261.86 × 379
  4. Step 4: Simplify right side
    840.70x = 478,244.94
  5. Step 5: Solve for x
    x = 478,244.94/840.70
  6. Step 6: Final answer
    x = 568.87

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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.