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Finding the Fourth Proportional to 728.21, 1,092.21 and 208.16

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Solution

The fourth proportional to 728.21, 1,092.21 and 208.16 is: 312.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.21 : 1,092.21 = 208.16 : x
  2. Step 2: Convert to fraction form
    728.21/1,092.21 = 208.16/x
  3. Step 3: Cross multiply
    728.21x = 1,092.21 × 208.16
  4. Step 4: Simplify right side
    728.21x = 227,354.43
  5. Step 5: Solve for x
    x = 227,354.43/728.21
  6. Step 6: Final answer
    x = 312.21

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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.