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Finding the Fourth Proportional to 285.70, 428.72 and 121.16

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Solution

The fourth proportional to 285.70, 428.72 and 121.16 is: 181.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.70 : 428.72 = 121.16 : x
  2. Step 2: Convert to fraction form
    285.70/428.72 = 121.16/x
  3. Step 3: Cross multiply
    285.70x = 428.72 × 121.16
  4. Step 4: Simplify right side
    285.70x = 51,942.71
  5. Step 5: Solve for x
    x = 51,942.71/285.70
  6. Step 6: Final answer
    x = 181.81

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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.