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Finding the Fourth Proportional to 718.76, 991.90 and 408.26

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Solution

The fourth proportional to 718.76, 991.90 and 408.26 is: 563.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.76 : 991.90 = 408.26 : x
  2. Step 2: Convert to fraction form
    718.76/991.90 = 408.26/x
  3. Step 3: Cross multiply
    718.76x = 991.90 × 408.26
  4. Step 4: Simplify right side
    718.76x = 404,953.09
  5. Step 5: Solve for x
    x = 404,953.09/718.76
  6. Step 6: Final answer
    x = 563.41

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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.