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Finding the Fourth Proportional to 1,288.71, 1,778.41 and 699.25

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Solution

The fourth proportional to 1,288.71, 1,778.41 and 699.25 is: 964.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.71 : 1,778.41 = 699.25 : x
  2. Step 2: Convert to fraction form
    1,288.71/1,778.41 = 699.25/x
  3. Step 3: Cross multiply
    1,288.71x = 1,778.41 × 699.25
  4. Step 4: Simplify right side
    1,288.71x = 1,243,553.19
  5. Step 5: Solve for x
    x = 1,243,553.19/1,288.71
  6. Step 6: Final answer
    x = 964.96

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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.