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Finding the Fourth Proportional to 428.33, 643.70 and 255.03

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Solution

The fourth proportional to 428.33, 643.70 and 255.03 is: 383.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.33 : 643.70 = 255.03 : x
  2. Step 2: Convert to fraction form
    428.33/643.70 = 255.03/x
  3. Step 3: Cross multiply
    428.33x = 643.70 × 255.03
  4. Step 4: Simplify right side
    428.33x = 164,162.81
  5. Step 5: Solve for x
    x = 164,162.81/428.33
  6. Step 6: Final answer
    x = 383.26

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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.