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Finding the Fourth Proportional to 285.40, 428.15 and 120.97

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Solution

The fourth proportional to 285.40, 428.15 and 120.97 is: 181.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.40 : 428.15 = 120.97 : x
  2. Step 2: Convert to fraction form
    285.40/428.15 = 120.97/x
  3. Step 3: Cross multiply
    285.40x = 428.15 × 120.97
  4. Step 4: Simplify right side
    285.40x = 51,790.56
  5. Step 5: Solve for x
    x = 51,790.56/285.40
  6. Step 6: Final answer
    x = 181.47

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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.