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Finding the Fourth Proportional to 421.05, 581.15 and 255.21

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Solution

The fourth proportional to 421.05, 581.15 and 255.21 is: 352.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.05 : 581.15 = 255.21 : x
  2. Step 2: Convert to fraction form
    421.05/581.15 = 255.21/x
  3. Step 3: Cross multiply
    421.05x = 581.15 × 255.21
  4. Step 4: Simplify right side
    421.05x = 148,313.44
  5. Step 5: Solve for x
    x = 148,313.44/421.05
  6. Step 6: Final answer
    x = 352.24

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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.