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Finding the Fourth Proportional to 100.58, 150.30 and 81.11

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Solution

The fourth proportional to 100.58, 150.30 and 81.11 is: 121.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.58 : 150.30 = 81.11 : x
  2. Step 2: Convert to fraction form
    100.58/150.30 = 81.11/x
  3. Step 3: Cross multiply
    100.58x = 150.30 × 81.11
  4. Step 4: Simplify right side
    100.58x = 12,190.08
  5. Step 5: Solve for x
    x = 12,190.08/100.58
  6. Step 6: Final answer
    x = 121.20

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.