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Finding the Fourth Proportional to 85.07, 127.39 and 72.15

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Solution

The fourth proportional to 85.07, 127.39 and 72.15 is: 108.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.07 : 127.39 = 72.15 : x
  2. Step 2: Convert to fraction form
    85.07/127.39 = 72.15/x
  3. Step 3: Cross multiply
    85.07x = 127.39 × 72.15
  4. Step 4: Simplify right side
    85.07x = 9,191.01
  5. Step 5: Solve for x
    x = 9,191.01/85.07
  6. Step 6: Final answer
    x = 108.05

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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.