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Finding the Fourth Proportional to 872.70, 1,302.20 and 728.70

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Solution

The fourth proportional to 872.70, 1,302.20 and 728.70 is: 1,087.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.70 : 1,302.20 = 728.70 : x
  2. Step 2: Convert to fraction form
    872.70/1,302.20 = 728.70/x
  3. Step 3: Cross multiply
    872.70x = 1,302.20 × 728.70
  4. Step 4: Simplify right side
    872.70x = 948,909.50
  5. Step 5: Solve for x
    x = 948,909.50/872.70
  6. Step 6: Final answer
    x = 1,087.33

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.