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Finding the Fourth Proportional to 803.81, 1,205.72 and 438.90

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Solution

The fourth proportional to 803.81, 1,205.72 and 438.90 is: 658.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    803.81 : 1,205.72 = 438.90 : x
  2. Step 2: Convert to fraction form
    803.81/1,205.72 = 438.90/x
  3. Step 3: Cross multiply
    803.81x = 1,205.72 × 438.90
  4. Step 4: Simplify right side
    803.81x = 529,188.31
  5. Step 5: Solve for x
    x = 529,188.31/803.81
  6. Step 6: Final answer
    x = 658.35

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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.