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Finding the Fourth Proportional to 939.27, 1,407.70 and 688.80

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Solution

The fourth proportional to 939.27, 1,407.70 and 688.80 is: 1,032.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    939.27 : 1,407.70 = 688.80 : x
  2. Step 2: Convert to fraction form
    939.27/1,407.70 = 688.80/x
  3. Step 3: Cross multiply
    939.27x = 1,407.70 × 688.80
  4. Step 4: Simplify right side
    939.27x = 969,623.76
  5. Step 5: Solve for x
    x = 969,623.76/939.27
  6. Step 6: Final answer
    x = 1,032.32

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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.