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Finding the Fourth Proportional to 665.79, 999.08 and 255.21

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Solution

The fourth proportional to 665.79, 999.08 and 255.21 is: 382.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.79 : 999.08 = 255.21 : x
  2. Step 2: Convert to fraction form
    665.79/999.08 = 255.21/x
  3. Step 3: Cross multiply
    665.79x = 999.08 × 255.21
  4. Step 4: Simplify right side
    665.79x = 254,973.93
  5. Step 5: Solve for x
    x = 254,973.93/665.79
  6. Step 6: Final answer
    x = 382.96

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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.