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Finding the Fourth Proportional to 718.98, 991.21 and 519.75

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Solution

The fourth proportional to 718.98, 991.21 and 519.75 is: 716.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.98 : 991.21 = 519.75 : x
  2. Step 2: Convert to fraction form
    718.98/991.21 = 519.75/x
  3. Step 3: Cross multiply
    718.98x = 991.21 × 519.75
  4. Step 4: Simplify right side
    718.98x = 515,186.72
  5. Step 5: Solve for x
    x = 515,186.72/718.98
  6. Step 6: Final answer
    x = 716.56

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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.