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Finding the Fourth Proportional to 718.31, 991.23 and 407.81

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Solution

The fourth proportional to 718.31, 991.23 and 407.81 is: 562.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.31 : 991.23 = 407.81 : x
  2. Step 2: Convert to fraction form
    718.31/991.23 = 407.81/x
  3. Step 3: Cross multiply
    718.31x = 991.23 × 407.81
  4. Step 4: Simplify right side
    718.31x = 404,228.55
  5. Step 5: Solve for x
    x = 404,228.55/718.31
  6. Step 6: Final answer
    x = 562.75

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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.