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Finding the Fourth Proportional to 861.48, 1,283.52 and 820.20

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Solution

The fourth proportional to 861.48, 1,283.52 and 820.20 is: 1,222.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.48 : 1,283.52 = 820.20 : x
  2. Step 2: Convert to fraction form
    861.48/1,283.52 = 820.20/x
  3. Step 3: Cross multiply
    861.48x = 1,283.52 × 820.20
  4. Step 4: Simplify right side
    861.48x = 1,052,743.10
  5. Step 5: Solve for x
    x = 1,052,743.10/861.48
  6. Step 6: Final answer
    x = 1,222.02

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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.