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Finding the Fourth Proportional to 208.25, 287.45 and 139.25

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Solution

The fourth proportional to 208.25, 287.45 and 139.25 is: 192.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.25 : 287.45 = 139.25 : x
  2. Step 2: Convert to fraction form
    208.25/287.45 = 139.25/x
  3. Step 3: Cross multiply
    208.25x = 287.45 × 139.25
  4. Step 4: Simplify right side
    208.25x = 40,027.41
  5. Step 5: Solve for x
    x = 40,027.41/208.25
  6. Step 6: Final answer
    x = 192.21

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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.