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Finding the Fourth Proportional to 1,281.69, 1,921.73 and 665.69

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Solution

The fourth proportional to 1,281.69, 1,921.73 and 665.69 is: 998.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,281.69 : 1,921.73 = 665.69 : x
  2. Step 2: Convert to fraction form
    1,281.69/1,921.73 = 665.69/x
  3. Step 3: Cross multiply
    1,281.69x = 1,921.73 × 665.69
  4. Step 4: Simplify right side
    1,281.69x = 1,279,263.51
  5. Step 5: Solve for x
    x = 1,279,263.51/1,281.69
  6. Step 6: Final answer
    x = 998.11

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.