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Finding the Fourth Proportional to 428.42, 643.38 and 406.52

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Solution

The fourth proportional to 428.42, 643.38 and 406.52 is: 610.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.42 : 643.38 = 406.52 : x
  2. Step 2: Convert to fraction form
    428.42/643.38 = 406.52/x
  3. Step 3: Cross multiply
    428.42x = 643.38 × 406.52
  4. Step 4: Simplify right side
    428.42x = 261,544.51
  5. Step 5: Solve for x
    x = 261,544.51/428.42
  6. Step 6: Final answer
    x = 610.48

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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.