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Finding the Fourth Proportional to 128.18, 190.86 and 127.58

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Solution

The fourth proportional to 128.18, 190.86 and 127.58 is: 189.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.18 : 190.86 = 127.58 : x
  2. Step 2: Convert to fraction form
    128.18/190.86 = 127.58/x
  3. Step 3: Cross multiply
    128.18x = 190.86 × 127.58
  4. Step 4: Simplify right side
    128.18x = 24,348.49
  5. Step 5: Solve for x
    x = 24,348.49/128.18
  6. Step 6: Final answer
    x = 189.95

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.