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Finding the Fourth Proportional to 828.70, 1,142.94 and 728.90

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Solution

The fourth proportional to 828.70, 1,142.94 and 728.90 is: 1,005.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.70 : 1,142.94 = 728.90 : x
  2. Step 2: Convert to fraction form
    828.70/1,142.94 = 728.90/x
  3. Step 3: Cross multiply
    828.70x = 1,142.94 × 728.90
  4. Step 4: Simplify right side
    828.70x = 833,088.97
  5. Step 5: Solve for x
    x = 833,088.97/828.70
  6. Step 6: Final answer
    x = 1,005.30

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.