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Finding the Fourth Proportional to 644.58, 889.40 and 378.99

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Solution

The fourth proportional to 644.58, 889.40 and 378.99 is: 522.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.58 : 889.40 = 378.99 : x
  2. Step 2: Convert to fraction form
    644.58/889.40 = 378.99/x
  3. Step 3: Cross multiply
    644.58x = 889.40 × 378.99
  4. Step 4: Simplify right side
    644.58x = 337,071.81
  5. Step 5: Solve for x
    x = 337,071.81/644.58
  6. Step 6: Final answer
    x = 522.93

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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.