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Finding the Fourth Proportional to 661.32, 991.58 and 455.66

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Solution

The fourth proportional to 661.32, 991.58 and 455.66 is: 683.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.32 : 991.58 = 455.66 : x
  2. Step 2: Convert to fraction form
    661.32/991.58 = 455.66/x
  3. Step 3: Cross multiply
    661.32x = 991.58 × 455.66
  4. Step 4: Simplify right side
    661.32x = 451,819.83
  5. Step 5: Solve for x
    x = 451,819.83/661.32
  6. Step 6: Final answer
    x = 683.21

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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.