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Finding the Fourth Proportional to 149.97, 206.78 and 100.74

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Solution

The fourth proportional to 149.97, 206.78 and 100.74 is: 138.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    149.97 : 206.78 = 100.74 : x
  2. Step 2: Convert to fraction form
    149.97/206.78 = 100.74/x
  3. Step 3: Cross multiply
    149.97x = 206.78 × 100.74
  4. Step 4: Simplify right side
    149.97x = 20,830.51
  5. Step 5: Solve for x
    x = 20,830.51/149.97
  6. Step 6: Final answer
    x = 138.90

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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.