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Finding the Fourth Proportional to 101.39, 138.78 and 100.58

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Solution

The fourth proportional to 101.39, 138.78 and 100.58 is: 137.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.39 : 138.78 = 100.58 : x
  2. Step 2: Convert to fraction form
    101.39/138.78 = 100.58/x
  3. Step 3: Cross multiply
    101.39x = 138.78 × 100.58
  4. Step 4: Simplify right side
    101.39x = 13,957.80
  5. Step 5: Solve for x
    x = 13,957.80/101.39
  6. Step 6: Final answer
    x = 137.67

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.