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Finding the Fourth Proportional to 818.40, 1,129.62 and 519.69

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Solution

The fourth proportional to 818.40, 1,129.62 and 519.69 is: 717.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.40 : 1,129.62 = 519.69 : x
  2. Step 2: Convert to fraction form
    818.40/1,129.62 = 519.69/x
  3. Step 3: Cross multiply
    818.40x = 1,129.62 × 519.69
  4. Step 4: Simplify right side
    818.40x = 587,052.22
  5. Step 5: Solve for x
    x = 587,052.22/818.40
  6. Step 6: Final answer
    x = 717.32

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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.