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Finding the Fourth Proportional to 278.80, 384.45 and 208.75

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Solution

The fourth proportional to 278.80, 384.45 and 208.75 is: 287.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.80 : 384.45 = 208.75 : x
  2. Step 2: Convert to fraction form
    278.80/384.45 = 208.75/x
  3. Step 3: Cross multiply
    278.80x = 384.45 × 208.75
  4. Step 4: Simplify right side
    278.80x = 80,253.94
  5. Step 5: Solve for x
    x = 80,253.94/278.80
  6. Step 6: Final answer
    x = 287.85

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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.