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Finding the Fourth Proportional to 389.96, 585.40 and 388.20

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Solution

The fourth proportional to 389.96, 585.40 and 388.20 is: 582.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.96 : 585.40 = 388.20 : x
  2. Step 2: Convert to fraction form
    389.96/585.40 = 388.20/x
  3. Step 3: Cross multiply
    389.96x = 585.40 × 388.20
  4. Step 4: Simplify right side
    389.96x = 227,252.28
  5. Step 5: Solve for x
    x = 227,252.28/389.96
  6. Step 6: Final answer
    x = 582.76

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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.