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Finding the Fourth Proportional to 770.85, 1,063.89 and 491.20

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Solution

The fourth proportional to 770.85, 1,063.89 and 491.20 is: 677.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.85 : 1,063.89 = 491.20 : x
  2. Step 2: Convert to fraction form
    770.85/1,063.89 = 491.20/x
  3. Step 3: Cross multiply
    770.85x = 1,063.89 × 491.20
  4. Step 4: Simplify right side
    770.85x = 522,580.11
  5. Step 5: Solve for x
    x = 522,580.11/770.85
  6. Step 6: Final answer
    x = 677.93

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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.