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Finding the Fourth Proportional to 718.40, 991.39 and 403.69

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Solution

The fourth proportional to 718.40, 991.39 and 403.69 is: 557.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.40 : 991.39 = 403.69 : x
  2. Step 2: Convert to fraction form
    718.40/991.39 = 403.69/x
  3. Step 3: Cross multiply
    718.40x = 991.39 × 403.69
  4. Step 4: Simplify right side
    718.40x = 400,214.23
  5. Step 5: Solve for x
    x = 400,214.23/718.40
  6. Step 6: Final answer
    x = 557.09

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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.