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Finding the Fourth Proportional to 121.30, 181.86 and 87.10

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Solution

The fourth proportional to 121.30, 181.86 and 87.10 is: 130.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.30 : 181.86 = 87.10 : x
  2. Step 2: Convert to fraction form
    121.30/181.86 = 87.10/x
  3. Step 3: Cross multiply
    121.30x = 181.86 × 87.10
  4. Step 4: Simplify right side
    121.30x = 15,840.01
  5. Step 5: Solve for x
    x = 15,840.01/121.30
  6. Step 6: Final answer
    x = 130.59

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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.