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Finding the Fourth Proportional to 666.81, 1,000.40 and 255.99

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Solution

The fourth proportional to 666.81, 1,000.40 and 255.99 is: 384.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.81 : 1,000.40 = 255.99 : x
  2. Step 2: Convert to fraction form
    666.81/1,000.40 = 255.99/x
  3. Step 3: Cross multiply
    666.81x = 1,000.40 × 255.99
  4. Step 4: Simplify right side
    666.81x = 256,091.12
  5. Step 5: Solve for x
    x = 256,091.12/666.81
  6. Step 6: Final answer
    x = 384.05

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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.