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Finding the Fourth Proportional to 939.32, 1,296.63 and 840.90

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Solution

The fourth proportional to 939.32, 1,296.63 and 840.90 is: 1,160.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    939.32 : 1,296.63 = 840.90 : x
  2. Step 2: Convert to fraction form
    939.32/1,296.63 = 840.90/x
  3. Step 3: Cross multiply
    939.32x = 1,296.63 × 840.90
  4. Step 4: Simplify right side
    939.32x = 1,090,336.17
  5. Step 5: Solve for x
    x = 1,090,336.17/939.32
  6. Step 6: Final answer
    x = 1,160.77

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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.