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Finding the Fourth Proportional to 1,288.64, 1,778.32 and 699.18

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Solution

The fourth proportional to 1,288.64, 1,778.32 and 699.18 is: 964.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.64 : 1,778.32 = 699.18 : x
  2. Step 2: Convert to fraction form
    1,288.64/1,778.32 = 699.18/x
  3. Step 3: Cross multiply
    1,288.64x = 1,778.32 × 699.18
  4. Step 4: Simplify right side
    1,288.64x = 1,243,365.78
  5. Step 5: Solve for x
    x = 1,243,365.78/1,288.64
  6. Step 6: Final answer
    x = 964.87

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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.