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Finding the Fourth Proportional to 861.09, 1,290.42 and 397.71

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Solution

The fourth proportional to 861.09, 1,290.42 and 397.71 is: 596.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.09 : 1,290.42 = 397.71 : x
  2. Step 2: Convert to fraction form
    861.09/1,290.42 = 397.71/x
  3. Step 3: Cross multiply
    861.09x = 1,290.42 × 397.71
  4. Step 4: Simplify right side
    861.09x = 513,212.94
  5. Step 5: Solve for x
    x = 513,212.94/861.09
  6. Step 6: Final answer
    x = 596.00

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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.