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Finding the Fourth Proportional to 770.70, 1,063.78 and 490.80

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Solution

The fourth proportional to 770.70, 1,063.78 and 490.80 is: 677.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.70 : 1,063.78 = 490.80 : x
  2. Step 2: Convert to fraction form
    770.70/1,063.78 = 490.80/x
  3. Step 3: Cross multiply
    770.70x = 1,063.78 × 490.80
  4. Step 4: Simplify right side
    770.70x = 522,103.22
  5. Step 5: Solve for x
    x = 522,103.22/770.70
  6. Step 6: Final answer
    x = 677.44

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.