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Finding the Fourth Proportional to 991.29, 1,489.25 and 580.71

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Solution

The fourth proportional to 991.29, 1,489.25 and 580.71 is: 872.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    991.29 : 1,489.25 = 580.71 : x
  2. Step 2: Convert to fraction form
    991.29/1,489.25 = 580.71/x
  3. Step 3: Cross multiply
    991.29x = 1,489.25 × 580.71
  4. Step 4: Simplify right side
    991.29x = 864,822.37
  5. Step 5: Solve for x
    x = 864,822.37/991.29
  6. Step 6: Final answer
    x = 872.42

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.