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Finding the Fourth Proportional to 813.85, 1,220.87 and 266.05

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Solution

The fourth proportional to 813.85, 1,220.87 and 266.05 is: 399.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.85 : 1,220.87 = 266.05 : x
  2. Step 2: Convert to fraction form
    813.85/1,220.87 = 266.05/x
  3. Step 3: Cross multiply
    813.85x = 1,220.87 × 266.05
  4. Step 4: Simplify right side
    813.85x = 324,812.46
  5. Step 5: Solve for x
    x = 324,812.46/813.85
  6. Step 6: Final answer
    x = 399.11

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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.