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Finding the Fourth Proportional to 728.18, 1,091.88 and 380.67

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Solution

The fourth proportional to 728.18, 1,091.88 and 380.67 is: 570.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.18 : 1,091.88 = 380.67 : x
  2. Step 2: Convert to fraction form
    728.18/1,091.88 = 380.67/x
  3. Step 3: Cross multiply
    728.18x = 1,091.88 × 380.67
  4. Step 4: Simplify right side
    728.18x = 415,645.96
  5. Step 5: Solve for x
    x = 415,645.96/728.18
  6. Step 6: Final answer
    x = 570.80

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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.