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Finding the Fourth Proportional to 113.57, 170.27 and 86.21

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Solution

The fourth proportional to 113.57, 170.27 and 86.21 is: 129.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    113.57 : 170.27 = 86.21 : x
  2. Step 2: Convert to fraction form
    113.57/170.27 = 86.21/x
  3. Step 3: Cross multiply
    113.57x = 170.27 × 86.21
  4. Step 4: Simplify right side
    113.57x = 14,678.55
  5. Step 5: Solve for x
    x = 14,678.55/113.57
  6. Step 6: Final answer
    x = 129.25

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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.