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Finding the Fourth Proportional to 870, 1,305.73 and 815.27

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Solution

The fourth proportional to 870, 1,305.73 and 815.27 is: 1,223.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    870 : 1,305.73 = 815.27 : x
  2. Step 2: Convert to fraction form
    870/1,305.73 = 815.27/x
  3. Step 3: Cross multiply
    870x = 1,305.73 × 815.27
  4. Step 4: Simplify right side
    870x = 1,064,522.50
  5. Step 5: Solve for x
    x = 1,064,522.50/870
  6. Step 6: Final answer
    x = 1,223.59

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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.