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Finding the Fourth Proportional to 1,397.91, 1,929.09 and 808.56

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Solution

The fourth proportional to 1,397.91, 1,929.09 and 808.56 is: 1,115.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,397.91 : 1,929.09 = 808.56 : x
  2. Step 2: Convert to fraction form
    1,397.91/1,929.09 = 808.56/x
  3. Step 3: Cross multiply
    1,397.91x = 1,929.09 × 808.56
  4. Step 4: Simplify right side
    1,397.91x = 1,559,785.01
  5. Step 5: Solve for x
    x = 1,559,785.01/1,397.91
  6. Step 6: Final answer
    x = 1,115.80

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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.