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Finding the Fourth Proportional to 142.03, 212.81 and 90.47

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Solution

The fourth proportional to 142.03, 212.81 and 90.47 is: 135.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.03 : 212.81 = 90.47 : x
  2. Step 2: Convert to fraction form
    142.03/212.81 = 90.47/x
  3. Step 3: Cross multiply
    142.03x = 212.81 × 90.47
  4. Step 4: Simplify right side
    142.03x = 19,252.92
  5. Step 5: Solve for x
    x = 19,252.92/142.03
  6. Step 6: Final answer
    x = 135.56

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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.