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Finding the Fourth Proportional to 644.49, 972.55 and 621.61

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Solution

The fourth proportional to 644.49, 972.55 and 621.61 is: 938.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.49 : 972.55 = 621.61 : x
  2. Step 2: Convert to fraction form
    644.49/972.55 = 621.61/x
  3. Step 3: Cross multiply
    644.49x = 972.55 × 621.61
  4. Step 4: Simplify right side
    644.49x = 604,546.81
  5. Step 5: Solve for x
    x = 604,546.81/644.49
  6. Step 6: Final answer
    x = 938.02

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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.