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Finding the Fourth Proportional to 840.21, 1,260.31 and 353.60

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Solution

The fourth proportional to 840.21, 1,260.31 and 353.60 is: 530.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.21 : 1,260.31 = 353.60 : x
  2. Step 2: Convert to fraction form
    840.21/1,260.31 = 353.60/x
  3. Step 3: Cross multiply
    840.21x = 1,260.31 × 353.60
  4. Step 4: Simplify right side
    840.21x = 445,645.62
  5. Step 5: Solve for x
    x = 445,645.62/840.21
  6. Step 6: Final answer
    x = 530.40

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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.