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Finding the Fourth Proportional to 770.70, 1,155.78 and 308.64

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Solution

The fourth proportional to 770.70, 1,155.78 and 308.64 is: 462.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.70 : 1,155.78 = 308.64 : x
  2. Step 2: Convert to fraction form
    770.70/1,155.78 = 308.64/x
  3. Step 3: Cross multiply
    770.70x = 1,155.78 × 308.64
  4. Step 4: Simplify right side
    770.70x = 356,719.94
  5. Step 5: Solve for x
    x = 356,719.94/770.70
  6. Step 6: Final answer
    x = 462.85

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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.