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Finding the Fourth Proportional to 121.17, 167.23 and 86.21

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Solution

The fourth proportional to 121.17, 167.23 and 86.21 is: 118.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.17 : 167.23 = 86.21 : x
  2. Step 2: Convert to fraction form
    121.17/167.23 = 86.21/x
  3. Step 3: Cross multiply
    121.17x = 167.23 × 86.21
  4. Step 4: Simplify right side
    121.17x = 14,416.90
  5. Step 5: Solve for x
    x = 14,416.90/121.17
  6. Step 6: Final answer
    x = 118.98

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.