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Finding the Fourth Proportional to 421.12, 580.57 and 281.26

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Solution

The fourth proportional to 421.12, 580.57 and 281.26 is: 387.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.12 : 580.57 = 281.26 : x
  2. Step 2: Convert to fraction form
    421.12/580.57 = 281.26/x
  3. Step 3: Cross multiply
    421.12x = 580.57 × 281.26
  4. Step 4: Simplify right side
    421.12x = 163,291.12
  5. Step 5: Solve for x
    x = 163,291.12/421.12
  6. Step 6: Final answer
    x = 387.75

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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.