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Finding the Fourth Proportional to 718.50, 991.71 and 408.18

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Solution

The fourth proportional to 718.50, 991.71 and 408.18 is: 563.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.50 : 991.71 = 408.18 : x
  2. Step 2: Convert to fraction form
    718.50/991.71 = 408.18/x
  3. Step 3: Cross multiply
    718.50x = 991.71 × 408.18
  4. Step 4: Simplify right side
    718.50x = 404,796.19
  5. Step 5: Solve for x
    x = 404,796.19/718.50
  6. Step 6: Final answer
    x = 563.39

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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.