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Finding the Fourth Proportional to 103.42, 142.70 and 66.57

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Solution

The fourth proportional to 103.42, 142.70 and 66.57 is: 91.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.42 : 142.70 = 66.57 : x
  2. Step 2: Convert to fraction form
    103.42/142.70 = 66.57/x
  3. Step 3: Cross multiply
    103.42x = 142.70 × 66.57
  4. Step 4: Simplify right side
    103.42x = 9,499.54
  5. Step 5: Solve for x
    x = 9,499.54/103.42
  6. Step 6: Final answer
    x = 91.85

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.