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Finding the Fourth Proportional to 386.90, 580.35 and 384.20

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Solution

The fourth proportional to 386.90, 580.35 and 384.20 is: 576.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.90 : 580.35 = 384.20 : x
  2. Step 2: Convert to fraction form
    386.90/580.35 = 384.20/x
  3. Step 3: Cross multiply
    386.90x = 580.35 × 384.20
  4. Step 4: Simplify right side
    386.90x = 222,970.47
  5. Step 5: Solve for x
    x = 222,970.47/386.90
  6. Step 6: Final answer
    x = 576.30

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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.