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Finding the Fourth Proportional to 421.78, 581.97 and 247.09

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Solution

The fourth proportional to 421.78, 581.97 and 247.09 is: 340.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.78 : 581.97 = 247.09 : x
  2. Step 2: Convert to fraction form
    421.78/581.97 = 247.09/x
  3. Step 3: Cross multiply
    421.78x = 581.97 × 247.09
  4. Step 4: Simplify right side
    421.78x = 143,798.97
  5. Step 5: Solve for x
    x = 143,798.97/421.78
  6. Step 6: Final answer
    x = 340.93

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.