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Finding the Fourth Proportional to 720.90, 995.18 and 422.11

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Solution

The fourth proportional to 720.90, 995.18 and 422.11 is: 582.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.90 : 995.18 = 422.11 : x
  2. Step 2: Convert to fraction form
    720.90/995.18 = 422.11/x
  3. Step 3: Cross multiply
    720.90x = 995.18 × 422.11
  4. Step 4: Simplify right side
    720.90x = 420,073.49
  5. Step 5: Solve for x
    x = 420,073.49/720.90
  6. Step 6: Final answer
    x = 582.70

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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.