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Finding the Fourth Proportional to 728.99, 1,090.91 and 455.21

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Solution

The fourth proportional to 728.99, 1,090.91 and 455.21 is: 681.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.99 : 1,090.91 = 455.21 : x
  2. Step 2: Convert to fraction form
    728.99/1,090.91 = 455.21/x
  3. Step 3: Cross multiply
    728.99x = 1,090.91 × 455.21
  4. Step 4: Simplify right side
    728.99x = 496,591.55
  5. Step 5: Solve for x
    x = 496,591.55/728.99
  6. Step 6: Final answer
    x = 681.21

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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.