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Finding the Fourth Proportional to 128.86, 176.87 and 117.93

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Solution

The fourth proportional to 128.86, 176.87 and 117.93 is: 161.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.86 : 176.87 = 117.93 : x
  2. Step 2: Convert to fraction form
    128.86/176.87 = 117.93/x
  3. Step 3: Cross multiply
    128.86x = 176.87 × 117.93
  4. Step 4: Simplify right side
    128.86x = 20,858.28
  5. Step 5: Solve for x
    x = 20,858.28/128.86
  6. Step 6: Final answer
    x = 161.87

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.