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Finding the Fourth Proportional to 393.60, 590.40 and 320.70

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Solution

The fourth proportional to 393.60, 590.40 and 320.70 is: 481.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    393.60 : 590.40 = 320.70 : x
  2. Step 2: Convert to fraction form
    393.60/590.40 = 320.70/x
  3. Step 3: Cross multiply
    393.60x = 590.40 × 320.70
  4. Step 4: Simplify right side
    393.60x = 189,341.28
  5. Step 5: Solve for x
    x = 189,341.28/393.60
  6. Step 6: Final answer
    x = 481.05

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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.