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Finding the Fourth Proportional to 803.70, 1,205.64 and 255.90

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Solution

The fourth proportional to 803.70, 1,205.64 and 255.90 is: 383.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    803.70 : 1,205.64 = 255.90 : x
  2. Step 2: Convert to fraction form
    803.70/1,205.64 = 255.90/x
  3. Step 3: Cross multiply
    803.70x = 1,205.64 × 255.90
  4. Step 4: Simplify right side
    803.70x = 308,523.28
  5. Step 5: Solve for x
    x = 308,523.28/803.70
  6. Step 6: Final answer
    x = 383.88

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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.