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Finding the Fourth Proportional to 142.48, 197.95 and 139.78

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Solution

The fourth proportional to 142.48, 197.95 and 139.78 is: 194.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.48 : 197.95 = 139.78 : x
  2. Step 2: Convert to fraction form
    142.48/197.95 = 139.78/x
  3. Step 3: Cross multiply
    142.48x = 197.95 × 139.78
  4. Step 4: Simplify right side
    142.48x = 27,669.45
  5. Step 5: Solve for x
    x = 27,669.45/142.48
  6. Step 6: Final answer
    x = 194.20

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.