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Finding the Fourth Proportional to 813.55, 1,219.61 and 380.59

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Solution

The fourth proportional to 813.55, 1,219.61 and 380.59 is: 570.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.55 : 1,219.61 = 380.59 : x
  2. Step 2: Convert to fraction form
    813.55/1,219.61 = 380.59/x
  3. Step 3: Cross multiply
    813.55x = 1,219.61 × 380.59
  4. Step 4: Simplify right side
    813.55x = 464,169.47
  5. Step 5: Solve for x
    x = 464,169.47/813.55
  6. Step 6: Final answer
    x = 570.55

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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.