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Finding the Fourth Proportional to 947.21, 1,308.42 and 728.87

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Solution

The fourth proportional to 947.21, 1,308.42 and 728.87 is: 1,006.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    947.21 : 1,308.42 = 728.87 : x
  2. Step 2: Convert to fraction form
    947.21/1,308.42 = 728.87/x
  3. Step 3: Cross multiply
    947.21x = 1,308.42 × 728.87
  4. Step 4: Simplify right side
    947.21x = 953,668.09
  5. Step 5: Solve for x
    x = 953,668.09/947.21
  6. Step 6: Final answer
    x = 1,006.82

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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.