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Finding the Fourth Proportional to 100.14, 138.21 and 61.35

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Solution

The fourth proportional to 100.14, 138.21 and 61.35 is: 84.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.14 : 138.21 = 61.35 : x
  2. Step 2: Convert to fraction form
    100.14/138.21 = 61.35/x
  3. Step 3: Cross multiply
    100.14x = 138.21 × 61.35
  4. Step 4: Simplify right side
    100.14x = 8,479.18
  5. Step 5: Solve for x
    x = 8,479.18/100.14
  6. Step 6: Final answer
    x = 84.67

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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.