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Finding the Fourth Proportional to 311.75, 430.41 and 278.94

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Solution

The fourth proportional to 311.75, 430.41 and 278.94 is: 385.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.75 : 430.41 = 278.94 : x
  2. Step 2: Convert to fraction form
    311.75/430.41 = 278.94/x
  3. Step 3: Cross multiply
    311.75x = 430.41 × 278.94
  4. Step 4: Simplify right side
    311.75x = 120,061.23
  5. Step 5: Solve for x
    x = 120,061.23/311.75
  6. Step 6: Final answer
    x = 385.12

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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.