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Finding the Fourth Proportional to 1,010.80, 1,396.32 and 780.88

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Solution

The fourth proportional to 1,010.80, 1,396.32 and 780.88 is: 1,078.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,010.80 : 1,396.32 = 780.88 : x
  2. Step 2: Convert to fraction form
    1,010.80/1,396.32 = 780.88/x
  3. Step 3: Cross multiply
    1,010.80x = 1,396.32 × 780.88
  4. Step 4: Simplify right side
    1,010.80x = 1,090,358.36
  5. Step 5: Solve for x
    x = 1,090,358.36/1,010.80
  6. Step 6: Final answer
    x = 1,078.71

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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.