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Finding the Fourth Proportional to 721.96, 996.30 and 390.38

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Solution

The fourth proportional to 721.96, 996.30 and 390.38 is: 538.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.96 : 996.30 = 390.38 : x
  2. Step 2: Convert to fraction form
    721.96/996.30 = 390.38/x
  3. Step 3: Cross multiply
    721.96x = 996.30 × 390.38
  4. Step 4: Simplify right side
    721.96x = 388,938.08
  5. Step 5: Solve for x
    x = 388,938.08/721.96
  6. Step 6: Final answer
    x = 538.73

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Double scale
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1.5x scale

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.