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Finding the Fourth Proportional to 840.81, 1,261.18 and 353.88

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Solution

The fourth proportional to 840.81, 1,261.18 and 353.88 is: 530.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.81 : 1,261.18 = 353.88 : x
  2. Step 2: Convert to fraction form
    840.81/1,261.18 = 353.88/x
  3. Step 3: Cross multiply
    840.81x = 1,261.18 × 353.88
  4. Step 4: Simplify right side
    840.81x = 446,306.38
  5. Step 5: Solve for x
    x = 446,306.38/840.81
  6. Step 6: Final answer
    x = 530.81

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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.