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Finding the Fourth Proportional to 669.87, 999.87 and 621

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Solution

The fourth proportional to 669.87, 999.87 and 621 is: 926.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.87 : 999.87 = 621 : x
  2. Step 2: Convert to fraction form
    669.87/999.87 = 621/x
  3. Step 3: Cross multiply
    669.87x = 999.87 × 621
  4. Step 4: Simplify right side
    669.87x = 620,919.27
  5. Step 5: Solve for x
    x = 620,919.27/669.87
  6. Step 6: Final answer
    x = 926.93

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.