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Finding the Fourth Proportional to 840.56, 1,261.62 and 429.99

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Solution

The fourth proportional to 840.56, 1,261.62 and 429.99 is: 645.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.56 : 1,261.62 = 429.99 : x
  2. Step 2: Convert to fraction form
    840.56/1,261.62 = 429.99/x
  3. Step 3: Cross multiply
    840.56x = 1,261.62 × 429.99
  4. Step 4: Simplify right side
    840.56x = 542,483.98
  5. Step 5: Solve for x
    x = 542,483.98/840.56
  6. Step 6: Final answer
    x = 645.38

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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.