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Finding the Fourth Proportional to 861.18, 1,290.81 and 495.66

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Solution

The fourth proportional to 861.18, 1,290.81 and 495.66 is: 742.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.18 : 1,290.81 = 495.66 : x
  2. Step 2: Convert to fraction form
    861.18/1,290.81 = 495.66/x
  3. Step 3: Cross multiply
    861.18x = 1,290.81 × 495.66
  4. Step 4: Simplify right side
    861.18x = 639,802.88
  5. Step 5: Solve for x
    x = 639,802.88/861.18
  6. Step 6: Final answer
    x = 742.94

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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.