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Finding the Fourth Proportional to 128.90, 193.12 and 124.67

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Solution

The fourth proportional to 128.90, 193.12 and 124.67 is: 186.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.90 : 193.12 = 124.67 : x
  2. Step 2: Convert to fraction form
    128.90/193.12 = 124.67/x
  3. Step 3: Cross multiply
    128.90x = 193.12 × 124.67
  4. Step 4: Simplify right side
    128.90x = 24,076.27
  5. Step 5: Solve for x
    x = 24,076.27/128.90
  6. Step 6: Final answer
    x = 186.78

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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.