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Finding the Fourth Proportional to 128.12, 176.94 and 89.48

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Solution

The fourth proportional to 128.12, 176.94 and 89.48 is: 123.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.12 : 176.94 = 89.48 : x
  2. Step 2: Convert to fraction form
    128.12/176.94 = 89.48/x
  3. Step 3: Cross multiply
    128.12x = 176.94 × 89.48
  4. Step 4: Simplify right side
    128.12x = 15,832.59
  5. Step 5: Solve for x
    x = 15,832.59/128.12
  6. Step 6: Final answer
    x = 123.58

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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.