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Finding the Fourth Proportional to 718.21, 991.09 and 403.53

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Solution

The fourth proportional to 718.21, 991.09 and 403.53 is: 556.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.21 : 991.09 = 403.53 : x
  2. Step 2: Convert to fraction form
    718.21/991.09 = 403.53/x
  3. Step 3: Cross multiply
    718.21x = 991.09 × 403.53
  4. Step 4: Simplify right side
    718.21x = 399,934.55
  5. Step 5: Solve for x
    x = 399,934.55/718.21
  6. Step 6: Final answer
    x = 556.85

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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.