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Finding the Fourth Proportional to 665.60, 1,003.38 and 621

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Solution

The fourth proportional to 665.60, 1,003.38 and 621 is: 936.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.60 : 1,003.38 = 621 : x
  2. Step 2: Convert to fraction form
    665.60/1,003.38 = 621/x
  3. Step 3: Cross multiply
    665.60x = 1,003.38 × 621
  4. Step 4: Simplify right side
    665.60x = 623,098.98
  5. Step 5: Solve for x
    x = 623,098.98/665.60
  6. Step 6: Final answer
    x = 936.15

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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.