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Finding the Fourth Proportional to 86.21, 129.30 and 25.34

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Solution

The fourth proportional to 86.21, 129.30 and 25.34 is: 38.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.21 : 129.30 = 25.34 : x
  2. Step 2: Convert to fraction form
    86.21/129.30 = 25.34/x
  3. Step 3: Cross multiply
    86.21x = 129.30 × 25.34
  4. Step 4: Simplify right side
    86.21x = 3,276.79
  5. Step 5: Solve for x
    x = 3,276.79/86.21
  6. Step 6: Final answer
    x = 38.01

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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.