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Finding the Fourth Proportional to 409.98, 615.30 and 312.78

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Solution

The fourth proportional to 409.98, 615.30 and 312.78 is: 469.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    409.98 : 615.30 = 312.78 : x
  2. Step 2: Convert to fraction form
    409.98/615.30 = 312.78/x
  3. Step 3: Cross multiply
    409.98x = 615.30 × 312.78
  4. Step 4: Simplify right side
    409.98x = 192,453.53
  5. Step 5: Solve for x
    x = 192,453.53/409.98
  6. Step 6: Final answer
    x = 469.42

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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.