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Finding the Fourth Proportional to 128.21, 191.25 and 118.62

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Solution

The fourth proportional to 128.21, 191.25 and 118.62 is: 176.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.21 : 191.25 = 118.62 : x
  2. Step 2: Convert to fraction form
    128.21/191.25 = 118.62/x
  3. Step 3: Cross multiply
    128.21x = 191.25 × 118.62
  4. Step 4: Simplify right side
    128.21x = 22,686.08
  5. Step 5: Solve for x
    x = 22,686.08/128.21
  6. Step 6: Final answer
    x = 176.95

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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.