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Finding the Fourth Proportional to 1,389.68, 1,918.09 and 800.56

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Solution

The fourth proportional to 1,389.68, 1,918.09 and 800.56 is: 1,104.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.68 : 1,918.09 = 800.56 : x
  2. Step 2: Convert to fraction form
    1,389.68/1,918.09 = 800.56/x
  3. Step 3: Cross multiply
    1,389.68x = 1,918.09 × 800.56
  4. Step 4: Simplify right side
    1,389.68x = 1,535,546.13
  5. Step 5: Solve for x
    x = 1,535,546.13/1,389.68
  6. Step 6: Final answer
    x = 1,104.96

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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.