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Finding the Fourth Proportional to 911.10, 1,255.59 and 689.70

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Solution

The fourth proportional to 911.10, 1,255.59 and 689.70 is: 950.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    911.10 : 1,255.59 = 689.70 : x
  2. Step 2: Convert to fraction form
    911.10/1,255.59 = 689.70/x
  3. Step 3: Cross multiply
    911.10x = 1,255.59 × 689.70
  4. Step 4: Simplify right side
    911.10x = 865,980.42
  5. Step 5: Solve for x
    x = 865,980.42/911.10
  6. Step 6: Final answer
    x = 950.48

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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.