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Finding the Fourth Proportional to 142.51, 213.78 and 55.85

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Solution

The fourth proportional to 142.51, 213.78 and 55.85 is: 83.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.51 : 213.78 = 55.85 : x
  2. Step 2: Convert to fraction form
    142.51/213.78 = 55.85/x
  3. Step 3: Cross multiply
    142.51x = 213.78 × 55.85
  4. Step 4: Simplify right side
    142.51x = 11,939.95
  5. Step 5: Solve for x
    x = 11,939.95/142.51
  6. Step 6: Final answer
    x = 83.78

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.