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Finding the Fourth Proportional to 208.88, 312.85 and 140.21

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Solution

The fourth proportional to 208.88, 312.85 and 140.21 is: 209.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.88 : 312.85 = 140.21 : x
  2. Step 2: Convert to fraction form
    208.88/312.85 = 140.21/x
  3. Step 3: Cross multiply
    208.88x = 312.85 × 140.21
  4. Step 4: Simplify right side
    208.88x = 43,862.81
  5. Step 5: Solve for x
    x = 43,862.81/208.88
  6. Step 6: Final answer
    x = 209.99

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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.