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Finding the Fourth Proportional to 86.08, 128.95 and 42.62

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Solution

The fourth proportional to 86.08, 128.95 and 42.62 is: 63.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.08 : 128.95 = 42.62 : x
  2. Step 2: Convert to fraction form
    86.08/128.95 = 42.62/x
  3. Step 3: Cross multiply
    86.08x = 128.95 × 42.62
  4. Step 4: Simplify right side
    86.08x = 5,495.63
  5. Step 5: Solve for x
    x = 5,495.63/86.08
  6. Step 6: Final answer
    x = 63.84

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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.