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Finding the Fourth Proportional to 208.35, 287.64 and 138.50

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Solution

The fourth proportional to 208.35, 287.64 and 138.50 is: 191.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.35 : 287.64 = 138.50 : x
  2. Step 2: Convert to fraction form
    208.35/287.64 = 138.50/x
  3. Step 3: Cross multiply
    208.35x = 287.64 × 138.50
  4. Step 4: Simplify right side
    208.35x = 39,838.86
  5. Step 5: Solve for x
    x = 39,838.86/208.35
  6. Step 6: Final answer
    x = 191.21

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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.