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Finding the Fourth Proportional to 718.28, 991.22 and 407.80

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Solution

The fourth proportional to 718.28, 991.22 and 407.80 is: 562.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.28 : 991.22 = 407.80 : x
  2. Step 2: Convert to fraction form
    718.28/991.22 = 407.80/x
  3. Step 3: Cross multiply
    718.28x = 991.22 × 407.80
  4. Step 4: Simplify right side
    718.28x = 404,219.52
  5. Step 5: Solve for x
    x = 404,219.52/718.28
  6. Step 6: Final answer
    x = 562.76

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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.