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Finding the Fourth Proportional to 853.80, 1,280.70 and 621.57

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Solution

The fourth proportional to 853.80, 1,280.70 and 621.57 is: 932.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.80 : 1,280.70 = 621.57 : x
  2. Step 2: Convert to fraction form
    853.80/1,280.70 = 621.57/x
  3. Step 3: Cross multiply
    853.80x = 1,280.70 × 621.57
  4. Step 4: Simplify right side
    853.80x = 796,044.70
  5. Step 5: Solve for x
    x = 796,044.70/853.80
  6. Step 6: Final answer
    x = 932.36

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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.