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Finding the Fourth Proportional to 121.12, 181.80 and 84.70

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Solution

The fourth proportional to 121.12, 181.80 and 84.70 is: 127.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.12 : 181.80 = 84.70 : x
  2. Step 2: Convert to fraction form
    121.12/181.80 = 84.70/x
  3. Step 3: Cross multiply
    121.12x = 181.80 × 84.70
  4. Step 4: Simplify right side
    121.12x = 15,398.46
  5. Step 5: Solve for x
    x = 15,398.46/121.12
  6. Step 6: Final answer
    x = 127.13

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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.