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Finding the Fourth Proportional to 615.15, 921.78 and 409.68

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Solution

The fourth proportional to 615.15, 921.78 and 409.68 is: 613.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    615.15 : 921.78 = 409.68 : x
  2. Step 2: Convert to fraction form
    615.15/921.78 = 409.68/x
  3. Step 3: Cross multiply
    615.15x = 921.78 × 409.68
  4. Step 4: Simplify right side
    615.15x = 377,634.83
  5. Step 5: Solve for x
    x = 377,634.83/615.15
  6. Step 6: Final answer
    x = 613.89

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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.