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Finding the Fourth Proportional to 939.72, 1,296.80 and 520

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Solution

The fourth proportional to 939.72, 1,296.80 and 520 is: 717.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    939.72 : 1,296.80 = 520 : x
  2. Step 2: Convert to fraction form
    939.72/1,296.80 = 520/x
  3. Step 3: Cross multiply
    939.72x = 1,296.80 × 520
  4. Step 4: Simplify right side
    939.72x = 674,336
  5. Step 5: Solve for x
    x = 674,336/939.72
  6. Step 6: Final answer
    x = 717.59

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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.