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Finding the Fourth Proportional to 768.50, 1,152.75 and 312.50

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Solution

The fourth proportional to 768.50, 1,152.75 and 312.50 is: 468.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.50 : 1,152.75 = 312.50 : x
  2. Step 2: Convert to fraction form
    768.50/1,152.75 = 312.50/x
  3. Step 3: Cross multiply
    768.50x = 1,152.75 × 312.50
  4. Step 4: Simplify right side
    768.50x = 360,234.38
  5. Step 5: Solve for x
    x = 360,234.38/768.50
  6. Step 6: Final answer
    x = 468.75

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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.