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Finding the Fourth Proportional to 840.97, 1,261.80 and 378.97

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Solution

The fourth proportional to 840.97, 1,261.80 and 378.97 is: 568.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.97 : 1,261.80 = 378.97 : x
  2. Step 2: Convert to fraction form
    840.97/1,261.80 = 378.97/x
  3. Step 3: Cross multiply
    840.97x = 1,261.80 × 378.97
  4. Step 4: Simplify right side
    840.97x = 478,178.08
  5. Step 5: Solve for x
    x = 478,178.08/840.97
  6. Step 6: Final answer
    x = 568.60

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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.