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Finding the Fourth Proportional to 86.08, 128.51 and 72.41

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Solution

The fourth proportional to 86.08, 128.51 and 72.41 is: 108.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.08 : 128.51 = 72.41 : x
  2. Step 2: Convert to fraction form
    86.08/128.51 = 72.41/x
  3. Step 3: Cross multiply
    86.08x = 128.51 × 72.41
  4. Step 4: Simplify right side
    86.08x = 9,304.40
  5. Step 5: Solve for x
    x = 9,304.40/86.08
  6. Step 6: Final answer
    x = 108.10

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.