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Finding the Fourth Proportional to 280.80, 388.80 and 259.20

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Solution

The fourth proportional to 280.80, 388.80 and 259.20 is: 358.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.80 : 388.80 = 259.20 : x
  2. Step 2: Convert to fraction form
    280.80/388.80 = 259.20/x
  3. Step 3: Cross multiply
    280.80x = 388.80 × 259.20
  4. Step 4: Simplify right side
    280.80x = 100,776.96
  5. Step 5: Solve for x
    x = 100,776.96/280.80
  6. Step 6: Final answer
    x = 358.89

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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.