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Finding the Fourth Proportional to 208.72, 311.36 and 187.12

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Solution

The fourth proportional to 208.72, 311.36 and 187.12 is: 279.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.72 : 311.36 = 187.12 : x
  2. Step 2: Convert to fraction form
    208.72/311.36 = 187.12/x
  3. Step 3: Cross multiply
    208.72x = 311.36 × 187.12
  4. Step 4: Simplify right side
    208.72x = 58,261.68
  5. Step 5: Solve for x
    x = 58,261.68/208.72
  6. Step 6: Final answer
    x = 279.14

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.