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Finding the Fourth Proportional to 142.80, 212.79 and 130.85

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Solution

The fourth proportional to 142.80, 212.79 and 130.85 is: 194.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.80 : 212.79 = 130.85 : x
  2. Step 2: Convert to fraction form
    142.80/212.79 = 130.85/x
  3. Step 3: Cross multiply
    142.80x = 212.79 × 130.85
  4. Step 4: Simplify right side
    142.80x = 27,843.80
  5. Step 5: Solve for x
    x = 27,843.80/142.80
  6. Step 6: Final answer
    x = 194.99

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.