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Finding the Fourth Proportional to 128.57, 192.71 and 59.99

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Solution

The fourth proportional to 128.57, 192.71 and 59.99 is: 89.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.57 : 192.71 = 59.99 : x
  2. Step 2: Convert to fraction form
    128.57/192.71 = 59.99/x
  3. Step 3: Cross multiply
    128.57x = 192.71 × 59.99
  4. Step 4: Simplify right side
    128.57x = 11,559.86
  5. Step 5: Solve for x
    x = 11,559.86/128.57
  6. Step 6: Final answer
    x = 89.91

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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.