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Finding the Fourth Proportional to 201.70, 278.19 and 155

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Solution

The fourth proportional to 201.70, 278.19 and 155 is: 213.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    201.70 : 278.19 = 155 : x
  2. Step 2: Convert to fraction form
    201.70/278.19 = 155/x
  3. Step 3: Cross multiply
    201.70x = 278.19 × 155
  4. Step 4: Simplify right side
    201.70x = 43,119.45
  5. Step 5: Solve for x
    x = 43,119.45/201.70
  6. Step 6: Final answer
    x = 213.78

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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.