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Finding the Fourth Proportional to 661.10, 991.71 and 309.96

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Solution

The fourth proportional to 661.10, 991.71 and 309.96 is: 464.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.10 : 991.71 = 309.96 : x
  2. Step 2: Convert to fraction form
    661.10/991.71 = 309.96/x
  3. Step 3: Cross multiply
    661.10x = 991.71 × 309.96
  4. Step 4: Simplify right side
    661.10x = 307,390.43
  5. Step 5: Solve for x
    x = 307,390.43/661.10
  6. Step 6: Final answer
    x = 464.97

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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.