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Finding the Fourth Proportional to 121.02, 166.86 and 100.20

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Solution

The fourth proportional to 121.02, 166.86 and 100.20 is: 138.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.02 : 166.86 = 100.20 : x
  2. Step 2: Convert to fraction form
    121.02/166.86 = 100.20/x
  3. Step 3: Cross multiply
    121.02x = 166.86 × 100.20
  4. Step 4: Simplify right side
    121.02x = 16,719.37
  5. Step 5: Solve for x
    x = 16,719.37/121.02
  6. Step 6: Final answer
    x = 138.15

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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.