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Finding the Fourth Proportional to 644.30, 889.18 and 469.70

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Solution

The fourth proportional to 644.30, 889.18 and 469.70 is: 648.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.30 : 889.18 = 469.70 : x
  2. Step 2: Convert to fraction form
    644.30/889.18 = 469.70/x
  3. Step 3: Cross multiply
    644.30x = 889.18 × 469.70
  4. Step 4: Simplify right side
    644.30x = 417,642.23
  5. Step 5: Solve for x
    x = 417,642.23/644.30
  6. Step 6: Final answer
    x = 648.22

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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.