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Finding the Fourth Proportional to 138.86, 191.64 and 100.07

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Solution

The fourth proportional to 138.86, 191.64 and 100.07 is: 138.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.86 : 191.64 = 100.07 : x
  2. Step 2: Convert to fraction form
    138.86/191.64 = 100.07/x
  3. Step 3: Cross multiply
    138.86x = 191.64 × 100.07
  4. Step 4: Simplify right side
    138.86x = 19,176.46
  5. Step 5: Solve for x
    x = 19,176.46/138.86
  6. Step 6: Final answer
    x = 138.10

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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.