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Finding the Fourth Proportional to 869.56, 1,305.78 and 485.08

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Solution

The fourth proportional to 869.56, 1,305.78 and 485.08 is: 728.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.56 : 1,305.78 = 485.08 : x
  2. Step 2: Convert to fraction form
    869.56/1,305.78 = 485.08/x
  3. Step 3: Cross multiply
    869.56x = 1,305.78 × 485.08
  4. Step 4: Simplify right side
    869.56x = 633,407.76
  5. Step 5: Solve for x
    x = 633,407.76/869.56
  6. Step 6: Final answer
    x = 728.42

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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.