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Finding the Fourth Proportional to 113.61, 170.15 and 72.90

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Solution

The fourth proportional to 113.61, 170.15 and 72.90 is: 109.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    113.61 : 170.15 = 72.90 : x
  2. Step 2: Convert to fraction form
    113.61/170.15 = 72.90/x
  3. Step 3: Cross multiply
    113.61x = 170.15 × 72.90
  4. Step 4: Simplify right side
    113.61x = 12,403.57
  5. Step 5: Solve for x
    x = 12,403.57/113.61
  6. Step 6: Final answer
    x = 109.18

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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.