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Finding the Fourth Proportional to 280.80, 387.54 and 275.40

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Solution

The fourth proportional to 280.80, 387.54 and 275.40 is: 380.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.80 : 387.54 = 275.40 : x
  2. Step 2: Convert to fraction form
    280.80/387.54 = 275.40/x
  3. Step 3: Cross multiply
    280.80x = 387.54 × 275.40
  4. Step 4: Simplify right side
    280.80x = 106,728.52
  5. Step 5: Solve for x
    x = 106,728.52/280.80
  6. Step 6: Final answer
    x = 380.09

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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.