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Finding the Fourth Proportional to 1,289.12, 1,778.98 and 699.65

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Solution

The fourth proportional to 1,289.12, 1,778.98 and 699.65 is: 965.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.12 : 1,778.98 = 699.65 : x
  2. Step 2: Convert to fraction form
    1,289.12/1,778.98 = 699.65/x
  3. Step 3: Cross multiply
    1,289.12x = 1,778.98 × 699.65
  4. Step 4: Simplify right side
    1,289.12x = 1,244,663.36
  5. Step 5: Solve for x
    x = 1,244,663.36/1,289.12
  6. Step 6: Final answer
    x = 965.51

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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.