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Finding the Fourth Proportional to 208.90, 312.81 and 127.63

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Solution

The fourth proportional to 208.90, 312.81 and 127.63 is: 191.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.90 : 312.81 = 127.63 : x
  2. Step 2: Convert to fraction form
    208.90/312.81 = 127.63/x
  3. Step 3: Cross multiply
    208.90x = 312.81 × 127.63
  4. Step 4: Simplify right side
    208.90x = 39,923.94
  5. Step 5: Solve for x
    x = 39,923.94/208.90
  6. Step 6: Final answer
    x = 191.12

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.