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Finding the Fourth Proportional to 718.65, 991.62 and 408.15

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Solution

The fourth proportional to 718.65, 991.62 and 408.15 is: 563.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.65 : 991.62 = 408.15 : x
  2. Step 2: Convert to fraction form
    718.65/991.62 = 408.15/x
  3. Step 3: Cross multiply
    718.65x = 991.62 × 408.15
  4. Step 4: Simplify right side
    718.65x = 404,729.70
  5. Step 5: Solve for x
    x = 404,729.70/718.65
  6. Step 6: Final answer
    x = 563.18

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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.