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Finding the Fourth Proportional to 721.78, 995.91 and 427.09

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Solution

The fourth proportional to 721.78, 995.91 and 427.09 is: 589.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.78 : 995.91 = 427.09 : x
  2. Step 2: Convert to fraction form
    721.78/995.91 = 427.09/x
  3. Step 3: Cross multiply
    721.78x = 995.91 × 427.09
  4. Step 4: Simplify right side
    721.78x = 425,343.20
  5. Step 5: Solve for x
    x = 425,343.20/721.78
  6. Step 6: Final answer
    x = 589.30

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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.