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Finding the Fourth Proportional to 947.70, 1,308.15 and 664.20

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Solution

The fourth proportional to 947.70, 1,308.15 and 664.20 is: 916.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    947.70 : 1,308.15 = 664.20 : x
  2. Step 2: Convert to fraction form
    947.70/1,308.15 = 664.20/x
  3. Step 3: Cross multiply
    947.70x = 1,308.15 × 664.20
  4. Step 4: Simplify right side
    947.70x = 868,873.23
  5. Step 5: Solve for x
    x = 868,873.23/947.70
  6. Step 6: Final answer
    x = 916.82

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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.