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Finding the Fourth Proportional to 280.49, 387.00 and 221.49

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Solution

The fourth proportional to 280.49, 387.00 and 221.49 is: 305.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.49 : 387.00 = 221.49 : x
  2. Step 2: Convert to fraction form
    280.49/387.00 = 221.49/x
  3. Step 3: Cross multiply
    280.49x = 387.00 × 221.49
  4. Step 4: Simplify right side
    280.49x = 85,716.12
  5. Step 5: Solve for x
    x = 85,716.12/280.49
  6. Step 6: Final answer
    x = 305.59

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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.