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Finding the Fourth Proportional to 662.78, 991.68 and 412.69

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Solution

The fourth proportional to 662.78, 991.68 and 412.69 is: 617.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    662.78 : 991.68 = 412.69 : x
  2. Step 2: Convert to fraction form
    662.78/991.68 = 412.69/x
  3. Step 3: Cross multiply
    662.78x = 991.68 × 412.69
  4. Step 4: Simplify right side
    662.78x = 409,256.42
  5. Step 5: Solve for x
    x = 409,256.42/662.78
  6. Step 6: Final answer
    x = 617.49

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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.