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Finding the Fourth Proportional to 121.80, 168.05 and 70.05

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Solution

The fourth proportional to 121.80, 168.05 and 70.05 is: 96.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.80 : 168.05 = 70.05 : x
  2. Step 2: Convert to fraction form
    121.80/168.05 = 70.05/x
  3. Step 3: Cross multiply
    121.80x = 168.05 × 70.05
  4. Step 4: Simplify right side
    121.80x = 11,771.90
  5. Step 5: Solve for x
    x = 11,771.90/121.80
  6. Step 6: Final answer
    x = 96.65

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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.