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Finding the Fourth Proportional to 1,221.71, 1,833.91 and 491.78

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Solution

The fourth proportional to 1,221.71, 1,833.91 and 491.78 is: 738.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,221.71 : 1,833.91 = 491.78 : x
  2. Step 2: Convert to fraction form
    1,221.71/1,833.91 = 491.78/x
  3. Step 3: Cross multiply
    1,221.71x = 1,833.91 × 491.78
  4. Step 4: Simplify right side
    1,221.71x = 901,883.62
  5. Step 5: Solve for x
    x = 901,883.62/1,221.71
  6. Step 6: Final answer
    x = 738.22

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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.