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Finding the Fourth Proportional to 621.88, 931.74 and 390.04

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Solution

The fourth proportional to 621.88, 931.74 and 390.04 is: 584.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.88 : 931.74 = 390.04 : x
  2. Step 2: Convert to fraction form
    621.88/931.74 = 390.04/x
  3. Step 3: Cross multiply
    621.88x = 931.74 × 390.04
  4. Step 4: Simplify right side
    621.88x = 363,415.87
  5. Step 5: Solve for x
    x = 363,415.87/621.88
  6. Step 6: Final answer
    x = 584.38

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.