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Finding the Fourth Proportional to 280.21, 420.12 and 254.74

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Solution

The fourth proportional to 280.21, 420.12 and 254.74 is: 381.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.21 : 420.12 = 254.74 : x
  2. Step 2: Convert to fraction form
    280.21/420.12 = 254.74/x
  3. Step 3: Cross multiply
    280.21x = 420.12 × 254.74
  4. Step 4: Simplify right side
    280.21x = 107,021.37
  5. Step 5: Solve for x
    x = 107,021.37/280.21
  6. Step 6: Final answer
    x = 381.93

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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.