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Finding the Fourth Proportional to 938.38, 1,293.77 and 643.14

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Solution

The fourth proportional to 938.38, 1,293.77 and 643.14 is: 886.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    938.38 : 1,293.77 = 643.14 : x
  2. Step 2: Convert to fraction form
    938.38/1,293.77 = 643.14/x
  3. Step 3: Cross multiply
    938.38x = 1,293.77 × 643.14
  4. Step 4: Simplify right side
    938.38x = 832,068.79
  5. Step 5: Solve for x
    x = 832,068.79/938.38
  6. Step 6: Final answer
    x = 886.71

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Double scale
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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.