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Finding the Fourth Proportional to 389.60, 583.20 and 320

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Solution

The fourth proportional to 389.60, 583.20 and 320 is: 479.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.60 : 583.20 = 320 : x
  2. Step 2: Convert to fraction form
    389.60/583.20 = 320/x
  3. Step 3: Cross multiply
    389.60x = 583.20 × 320
  4. Step 4: Simplify right side
    389.60x = 186,624
  5. Step 5: Solve for x
    x = 186,624/389.60
  6. Step 6: Final answer
    x = 479.01

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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.