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Finding the Fourth Proportional to 128.86, 193.29 and 98.48

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Solution

The fourth proportional to 128.86, 193.29 and 98.48 is: 147.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.86 : 193.29 = 98.48 : x
  2. Step 2: Convert to fraction form
    128.86/193.29 = 98.48/x
  3. Step 3: Cross multiply
    128.86x = 193.29 × 98.48
  4. Step 4: Simplify right side
    128.86x = 19,035.20
  5. Step 5: Solve for x
    x = 19,035.20/128.86
  6. Step 6: Final answer
    x = 147.72

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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.