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Finding the Fourth Proportional to 1,323.05, 1,983.13 and 861.15

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Solution

The fourth proportional to 1,323.05, 1,983.13 and 861.15 is: 1,290.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,323.05 : 1,983.13 = 861.15 : x
  2. Step 2: Convert to fraction form
    1,323.05/1,983.13 = 861.15/x
  3. Step 3: Cross multiply
    1,323.05x = 1,983.13 × 861.15
  4. Step 4: Simplify right side
    1,323.05x = 1,707,772.40
  5. Step 5: Solve for x
    x = 1,707,772.40/1,323.05
  6. Step 6: Final answer
    x = 1,290.78

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1.5x scale

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.