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Finding the Fourth Proportional to 1,376.80, 2,062.24 and 861.28

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Solution

The fourth proportional to 1,376.80, 2,062.24 and 861.28 is: 1,290.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,376.80 : 2,062.24 = 861.28 : x
  2. Step 2: Convert to fraction form
    1,376.80/2,062.24 = 861.28/x
  3. Step 3: Cross multiply
    1,376.80x = 2,062.24 × 861.28
  4. Step 4: Simplify right side
    1,376.80x = 1,776,166.07
  5. Step 5: Solve for x
    x = 1,776,166.07/1,376.80
  6. Step 6: Final answer
    x = 1,290.07

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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.