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Finding the Fourth Proportional to 820.16, 1,230.44 and 381.72

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Solution

The fourth proportional to 820.16, 1,230.44 and 381.72 is: 572.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.16 : 1,230.44 = 381.72 : x
  2. Step 2: Convert to fraction form
    820.16/1,230.44 = 381.72/x
  3. Step 3: Cross multiply
    820.16x = 1,230.44 × 381.72
  4. Step 4: Simplify right side
    820.16x = 469,683.56
  5. Step 5: Solve for x
    x = 469,683.56/820.16
  6. Step 6: Final answer
    x = 572.67

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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.