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Finding the Fourth Proportional to 501.45, 748.31 and 428.28

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Solution

The fourth proportional to 501.45, 748.31 and 428.28 is: 639.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    501.45 : 748.31 = 428.28 : x
  2. Step 2: Convert to fraction form
    501.45/748.31 = 428.28/x
  3. Step 3: Cross multiply
    501.45x = 748.31 × 428.28
  4. Step 4: Simplify right side
    501.45x = 320,486.21
  5. Step 5: Solve for x
    x = 320,486.21/501.45
  6. Step 6: Final answer
    x = 639.12

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.