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Finding the Fourth Proportional to 911.65, 1,257.31 and 770.55

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Solution

The fourth proportional to 911.65, 1,257.31 and 770.55 is: 1,062.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    911.65 : 1,257.31 = 770.55 : x
  2. Step 2: Convert to fraction form
    911.65/1,257.31 = 770.55/x
  3. Step 3: Cross multiply
    911.65x = 1,257.31 × 770.55
  4. Step 4: Simplify right side
    911.65x = 968,816.37
  5. Step 5: Solve for x
    x = 968,816.37/911.65
  6. Step 6: Final answer
    x = 1,062.71

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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.