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Finding the Fourth Proportional to 280.49, 387.75 and 257.14

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Solution

The fourth proportional to 280.49, 387.75 and 257.14 is: 355.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.49 : 387.75 = 257.14 : x
  2. Step 2: Convert to fraction form
    280.49/387.75 = 257.14/x
  3. Step 3: Cross multiply
    280.49x = 387.75 × 257.14
  4. Step 4: Simplify right side
    280.49x = 99,706.04
  5. Step 5: Solve for x
    x = 99,706.04/280.49
  6. Step 6: Final answer
    x = 355.47

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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.