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Finding the Fourth Proportional to 421.66, 581.80 and 255.87

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Solution

The fourth proportional to 421.66, 581.80 and 255.87 is: 353.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.66 : 581.80 = 255.87 : x
  2. Step 2: Convert to fraction form
    421.66/581.80 = 255.87/x
  3. Step 3: Cross multiply
    421.66x = 581.80 × 255.87
  4. Step 4: Simplify right side
    421.66x = 148,865.17
  5. Step 5: Solve for x
    x = 148,865.17/421.66
  6. Step 6: Final answer
    x = 353.05

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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.