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Finding the Fourth Proportional to 813.44, 1,220.16 and 380.90

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Solution

The fourth proportional to 813.44, 1,220.16 and 380.90 is: 571.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.44 : 1,220.16 = 380.90 : x
  2. Step 2: Convert to fraction form
    813.44/1,220.16 = 380.90/x
  3. Step 3: Cross multiply
    813.44x = 1,220.16 × 380.90
  4. Step 4: Simplify right side
    813.44x = 464,758.94
  5. Step 5: Solve for x
    x = 464,758.94/813.44
  6. Step 6: Final answer
    x = 571.35

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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.