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Finding the Fourth Proportional to 1,252.56, 1,728.55 and 780.65

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Solution

The fourth proportional to 1,252.56, 1,728.55 and 780.65 is: 1,077.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,252.56 : 1,728.55 = 780.65 : x
  2. Step 2: Convert to fraction form
    1,252.56/1,728.55 = 780.65/x
  3. Step 3: Cross multiply
    1,252.56x = 1,728.55 × 780.65
  4. Step 4: Simplify right side
    1,252.56x = 1,349,384.32
  5. Step 5: Solve for x
    x = 1,349,384.32/1,252.56
  6. Step 6: Final answer
    x = 1,077.30

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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.