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Finding the Fourth Proportional to 128.16, 191.86 and 112.16

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Solution

The fourth proportional to 128.16, 191.86 and 112.16 is: 167.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.16 : 191.86 = 112.16 : x
  2. Step 2: Convert to fraction form
    128.16/191.86 = 112.16/x
  3. Step 3: Cross multiply
    128.16x = 191.86 × 112.16
  4. Step 4: Simplify right side
    128.16x = 21,519.02
  5. Step 5: Solve for x
    x = 21,519.02/128.16
  6. Step 6: Final answer
    x = 167.91

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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.