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Finding the Fourth Proportional to 142.40, 213.70 and 84.60

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Solution

The fourth proportional to 142.40, 213.70 and 84.60 is: 126.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.40 : 213.70 = 84.60 : x
  2. Step 2: Convert to fraction form
    142.40/213.70 = 84.60/x
  3. Step 3: Cross multiply
    142.40x = 213.70 × 84.60
  4. Step 4: Simplify right side
    142.40x = 18,079.02
  5. Step 5: Solve for x
    x = 18,079.02/142.40
  6. Step 6: Final answer
    x = 126.96

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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.