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Finding the Fourth Proportional to 100.45, 138.63 and 67.77

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Solution

The fourth proportional to 100.45, 138.63 and 67.77 is: 93.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.45 : 138.63 = 67.77 : x
  2. Step 2: Convert to fraction form
    100.45/138.63 = 67.77/x
  3. Step 3: Cross multiply
    100.45x = 138.63 × 67.77
  4. Step 4: Simplify right side
    100.45x = 9,394.44
  5. Step 5: Solve for x
    x = 9,394.44/100.45
  6. Step 6: Final answer
    x = 93.53

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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.