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Finding the Fourth Proportional to 770.50, 1,155.78 and 308.50

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Solution

The fourth proportional to 770.50, 1,155.78 and 308.50 is: 462.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.50 : 1,155.78 = 308.50 : x
  2. Step 2: Convert to fraction form
    770.50/1,155.78 = 308.50/x
  3. Step 3: Cross multiply
    770.50x = 1,155.78 × 308.50
  4. Step 4: Simplify right side
    770.50x = 356,558.13
  5. Step 5: Solve for x
    x = 356,558.13/770.50
  6. Step 6: Final answer
    x = 462.76

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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.