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Finding the Fourth Proportional to 100.35, 138.47 and 58.91

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Solution

The fourth proportional to 100.35, 138.47 and 58.91 is: 81.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.35 : 138.47 = 58.91 : x
  2. Step 2: Convert to fraction form
    100.35/138.47 = 58.91/x
  3. Step 3: Cross multiply
    100.35x = 138.47 × 58.91
  4. Step 4: Simplify right side
    100.35x = 8,156.72
  5. Step 5: Solve for x
    x = 8,156.72/100.35
  6. Step 6: Final answer
    x = 81.28

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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.