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Finding the Fourth Proportional to 208.50, 287.58 and 134.78

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Solution

The fourth proportional to 208.50, 287.58 and 134.78 is: 185.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.50 : 287.58 = 134.78 : x
  2. Step 2: Convert to fraction form
    208.50/287.58 = 134.78/x
  3. Step 3: Cross multiply
    208.50x = 287.58 × 134.78
  4. Step 4: Simplify right side
    208.50x = 38,760.03
  5. Step 5: Solve for x
    x = 38,760.03/208.50
  6. Step 6: Final answer
    x = 185.90

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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.