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Finding the Fourth Proportional to 389.30, 584.40 and 386.60

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Solution

The fourth proportional to 389.30, 584.40 and 386.60 is: 580.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.30 : 584.40 = 386.60 : x
  2. Step 2: Convert to fraction form
    389.30/584.40 = 386.60/x
  3. Step 3: Cross multiply
    389.30x = 584.40 × 386.60
  4. Step 4: Simplify right side
    389.30x = 225,929.04
  5. Step 5: Solve for x
    x = 225,929.04/389.30
  6. Step 6: Final answer
    x = 580.35

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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.