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Finding the Fourth Proportional to 861.10, 1,188.30 and 641.02

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Solution

The fourth proportional to 861.10, 1,188.30 and 641.02 is: 884.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.10 : 1,188.30 = 641.02 : x
  2. Step 2: Convert to fraction form
    861.10/1,188.30 = 641.02/x
  3. Step 3: Cross multiply
    861.10x = 1,188.30 × 641.02
  4. Step 4: Simplify right side
    861.10x = 761,724.07
  5. Step 5: Solve for x
    x = 761,724.07/861.10
  6. Step 6: Final answer
    x = 884.59

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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.