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Finding the Fourth Proportional to 427.06, 644 and 421.28

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Solution

The fourth proportional to 427.06, 644 and 421.28 is: 635.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.06 : 644 = 421.28 : x
  2. Step 2: Convert to fraction form
    427.06/644 = 421.28/x
  3. Step 3: Cross multiply
    427.06x = 644 × 421.28
  4. Step 4: Simplify right side
    427.06x = 271,304.32
  5. Step 5: Solve for x
    x = 271,304.32/427.06
  6. Step 6: Final answer
    x = 635.28

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.