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Finding the Fourth Proportional to 1,313.67, 1,812.87 and 789.71

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Solution

The fourth proportional to 1,313.67, 1,812.87 and 789.71 is: 1,089.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,313.67 : 1,812.87 = 789.71 : x
  2. Step 2: Convert to fraction form
    1,313.67/1,812.87 = 789.71/x
  3. Step 3: Cross multiply
    1,313.67x = 1,812.87 × 789.71
  4. Step 4: Simplify right side
    1,313.67x = 1,431,641.57
  5. Step 5: Solve for x
    x = 1,431,641.57/1,313.67
  6. Step 6: Final answer
    x = 1,089.80

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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.