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Finding the Fourth Proportional to 216.60, 298.70 and 142.78

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Solution

The fourth proportional to 216.60, 298.70 and 142.78 is: 196.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.60 : 298.70 = 142.78 : x
  2. Step 2: Convert to fraction form
    216.60/298.70 = 142.78/x
  3. Step 3: Cross multiply
    216.60x = 298.70 × 142.78
  4. Step 4: Simplify right side
    216.60x = 42,648.39
  5. Step 5: Solve for x
    x = 42,648.39/216.60
  6. Step 6: Final answer
    x = 196.90

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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.