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Finding the Fourth Proportional to 521.69, 781.29 and 515.43

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Solution

The fourth proportional to 521.69, 781.29 and 515.43 is: 771.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.69 : 781.29 = 515.43 : x
  2. Step 2: Convert to fraction form
    521.69/781.29 = 515.43/x
  3. Step 3: Cross multiply
    521.69x = 781.29 × 515.43
  4. Step 4: Simplify right side
    521.69x = 402,700.30
  5. Step 5: Solve for x
    x = 402,700.30/521.69
  6. Step 6: Final answer
    x = 771.92

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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.