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Finding the Fourth Proportional to 427.35, 640.62 and 389.31

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Solution

The fourth proportional to 427.35, 640.62 and 389.31 is: 583.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.35 : 640.62 = 389.31 : x
  2. Step 2: Convert to fraction form
    427.35/640.62 = 389.31/x
  3. Step 3: Cross multiply
    427.35x = 640.62 × 389.31
  4. Step 4: Simplify right side
    427.35x = 249,396.57
  5. Step 5: Solve for x
    x = 249,396.57/427.35
  6. Step 6: Final answer
    x = 583.59

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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.