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Finding the Fourth Proportional to 142.08, 213.19 and 90.71

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Solution

The fourth proportional to 142.08, 213.19 and 90.71 is: 136.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.08 : 213.19 = 90.71 : x
  2. Step 2: Convert to fraction form
    142.08/213.19 = 90.71/x
  3. Step 3: Cross multiply
    142.08x = 213.19 × 90.71
  4. Step 4: Simplify right side
    142.08x = 19,338.46
  5. Step 5: Solve for x
    x = 19,338.46/142.08
  6. Step 6: Final answer
    x = 136.11

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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.