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Finding the Fourth Proportional to 208.22, 287.36 and 138.15

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Solution

The fourth proportional to 208.22, 287.36 and 138.15 is: 190.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.22 : 287.36 = 138.15 : x
  2. Step 2: Convert to fraction form
    208.22/287.36 = 138.15/x
  3. Step 3: Cross multiply
    208.22x = 287.36 × 138.15
  4. Step 4: Simplify right side
    208.22x = 39,698.09
  5. Step 5: Solve for x
    x = 39,698.09/208.22
  6. Step 6: Final answer
    x = 190.66

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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.