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Finding the Fourth Proportional to 138.32, 190.94 and 99.57

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Solution

The fourth proportional to 138.32, 190.94 and 99.57 is: 137.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.32 : 190.94 = 99.57 : x
  2. Step 2: Convert to fraction form
    138.32/190.94 = 99.57/x
  3. Step 3: Cross multiply
    138.32x = 190.94 × 99.57
  4. Step 4: Simplify right side
    138.32x = 19,011.90
  5. Step 5: Solve for x
    x = 19,011.90/138.32
  6. Step 6: Final answer
    x = 137.45

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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.