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Finding the Fourth Proportional to 128.10, 191.95 and 102.59

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Solution

The fourth proportional to 128.10, 191.95 and 102.59 is: 153.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.10 : 191.95 = 102.59 : x
  2. Step 2: Convert to fraction form
    128.10/191.95 = 102.59/x
  3. Step 3: Cross multiply
    128.10x = 191.95 × 102.59
  4. Step 4: Simplify right side
    128.10x = 19,690.93
  5. Step 5: Solve for x
    x = 19,690.93/128.10
  6. Step 6: Final answer
    x = 153.72

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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.