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Finding the Fourth Proportional to 1,288.26, 1,777.75 and 698.78

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Solution

The fourth proportional to 1,288.26, 1,777.75 and 698.78 is: 964.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.26 : 1,777.75 = 698.78 : x
  2. Step 2: Convert to fraction form
    1,288.26/1,777.75 = 698.78/x
  3. Step 3: Cross multiply
    1,288.26x = 1,777.75 × 698.78
  4. Step 4: Simplify right side
    1,288.26x = 1,242,260.59
  5. Step 5: Solve for x
    x = 1,242,260.59/1,288.26
  6. Step 6: Final answer
    x = 964.29

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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.