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Finding the Fourth Proportional to 869.88, 1,199.28 and 645.09

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Solution

The fourth proportional to 869.88, 1,199.28 and 645.09 is: 889.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.88 : 1,199.28 = 645.09 : x
  2. Step 2: Convert to fraction form
    869.88/1,199.28 = 645.09/x
  3. Step 3: Cross multiply
    869.88x = 1,199.28 × 645.09
  4. Step 4: Simplify right side
    869.88x = 773,643.54
  5. Step 5: Solve for x
    x = 773,643.54/869.88
  6. Step 6: Final answer
    x = 889.37

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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.