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Finding the Fourth Proportional to 1,661.24, 2,491.76 and 428.71

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Solution

The fourth proportional to 1,661.24, 2,491.76 and 428.71 is: 643.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,661.24 : 2,491.76 = 428.71 : x
  2. Step 2: Convert to fraction form
    1,661.24/2,491.76 = 428.71/x
  3. Step 3: Cross multiply
    1,661.24x = 2,491.76 × 428.71
  4. Step 4: Simplify right side
    1,661.24x = 1,068,237.27
  5. Step 5: Solve for x
    x = 1,068,237.27/1,661.24
  6. Step 6: Final answer
    x = 643.04

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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.