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Finding the Fourth Proportional to 1,220.69, 1,685.33 and 801.78

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Solution

The fourth proportional to 1,220.69, 1,685.33 and 801.78 is: 1,106.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,220.69 : 1,685.33 = 801.78 : x
  2. Step 2: Convert to fraction form
    1,220.69/1,685.33 = 801.78/x
  3. Step 3: Cross multiply
    1,220.69x = 1,685.33 × 801.78
  4. Step 4: Simplify right side
    1,220.69x = 1,351,259.88
  5. Step 5: Solve for x
    x = 1,351,259.88/1,220.69
  6. Step 6: Final answer
    x = 1,106.97

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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.