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Finding the Fourth Proportional to 390.30, 584.55 and 381.30

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Solution

The fourth proportional to 390.30, 584.55 and 381.30 is: 571.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.30 : 584.55 = 381.30 : x
  2. Step 2: Convert to fraction form
    390.30/584.55 = 381.30/x
  3. Step 3: Cross multiply
    390.30x = 584.55 × 381.30
  4. Step 4: Simplify right side
    390.30x = 222,888.92
  5. Step 5: Solve for x
    x = 222,888.92/390.30
  6. Step 6: Final answer
    x = 571.07

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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.