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Finding the Fourth Proportional to 644.34, 889.32 and 420.38

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Solution

The fourth proportional to 644.34, 889.32 and 420.38 is: 580.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.34 : 889.32 = 420.38 : x
  2. Step 2: Convert to fraction form
    644.34/889.32 = 420.38/x
  3. Step 3: Cross multiply
    644.34x = 889.32 × 420.38
  4. Step 4: Simplify right side
    644.34x = 373,852.34
  5. Step 5: Solve for x
    x = 373,852.34/644.34
  6. Step 6: Final answer
    x = 580.21

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.