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Finding the Fourth Proportional to 809.20, 1,115.48 and 587.80

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Solution

The fourth proportional to 809.20, 1,115.48 and 587.80 is: 810.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.20 : 1,115.48 = 587.80 : x
  2. Step 2: Convert to fraction form
    809.20/1,115.48 = 587.80/x
  3. Step 3: Cross multiply
    809.20x = 1,115.48 × 587.80
  4. Step 4: Simplify right side
    809.20x = 655,679.14
  5. Step 5: Solve for x
    x = 655,679.14/809.20
  6. Step 6: Final answer
    x = 810.28

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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.