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Finding the Fourth Proportional to 403.20, 608.40 and 389.70

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Solution

The fourth proportional to 403.20, 608.40 and 389.70 is: 588.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.20 : 608.40 = 389.70 : x
  2. Step 2: Convert to fraction form
    403.20/608.40 = 389.70/x
  3. Step 3: Cross multiply
    403.20x = 608.40 × 389.70
  4. Step 4: Simplify right side
    403.20x = 237,093.48
  5. Step 5: Solve for x
    x = 237,093.48/403.20
  6. Step 6: Final answer
    x = 588.03

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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.