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Finding the Fourth Proportional to 422.08, 582.80 and 318.40

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Solution

The fourth proportional to 422.08, 582.80 and 318.40 is: 439.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.08 : 582.80 = 318.40 : x
  2. Step 2: Convert to fraction form
    422.08/582.80 = 318.40/x
  3. Step 3: Cross multiply
    422.08x = 582.80 × 318.40
  4. Step 4: Simplify right side
    422.08x = 185,563.52
  5. Step 5: Solve for x
    x = 185,563.52/422.08
  6. Step 6: Final answer
    x = 439.64

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.