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Finding the Fourth Proportional to 640.84, 885.51 and 553.36

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Solution

The fourth proportional to 640.84, 885.51 and 553.36 is: 764.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.84 : 885.51 = 553.36 : x
  2. Step 2: Convert to fraction form
    640.84/885.51 = 553.36/x
  3. Step 3: Cross multiply
    640.84x = 885.51 × 553.36
  4. Step 4: Simplify right side
    640.84x = 490,005.81
  5. Step 5: Solve for x
    x = 490,005.81/640.84
  6. Step 6: Final answer
    x = 764.63

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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.