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Finding the Fourth Proportional to 1,820.81, 2,729.39 and 781.49

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Solution

The fourth proportional to 1,820.81, 2,729.39 and 781.49 is: 1,171.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,820.81 : 2,729.39 = 781.49 : x
  2. Step 2: Convert to fraction form
    1,820.81/2,729.39 = 781.49/x
  3. Step 3: Cross multiply
    1,820.81x = 2,729.39 × 781.49
  4. Step 4: Simplify right side
    1,820.81x = 2,132,973.44
  5. Step 5: Solve for x
    x = 2,132,973.44/1,820.81
  6. Step 6: Final answer
    x = 1,171.45

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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.