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Finding the Fourth Proportional to 728.20, 1,091.98 and 215.08

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Solution

The fourth proportional to 728.20, 1,091.98 and 215.08 is: 322.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.20 : 1,091.98 = 215.08 : x
  2. Step 2: Convert to fraction form
    728.20/1,091.98 = 215.08/x
  3. Step 3: Cross multiply
    728.20x = 1,091.98 × 215.08
  4. Step 4: Simplify right side
    728.20x = 234,863.06
  5. Step 5: Solve for x
    x = 234,863.06/728.20
  6. Step 6: Final answer
    x = 322.53

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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.