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Finding the Fourth Proportional to 840.98, 1,261.56 and 408.08

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Solution

The fourth proportional to 840.98, 1,261.56 and 408.08 is: 612.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.98 : 1,261.56 = 408.08 : x
  2. Step 2: Convert to fraction form
    840.98/1,261.56 = 408.08/x
  3. Step 3: Cross multiply
    840.98x = 1,261.56 × 408.08
  4. Step 4: Simplify right side
    840.98x = 514,817.40
  5. Step 5: Solve for x
    x = 514,817.40/840.98
  6. Step 6: Final answer
    x = 612.16

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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.