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Finding the Fourth Proportional to 871.32, 1,200.39 and 649.86

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Solution

The fourth proportional to 871.32, 1,200.39 and 649.86 is: 895.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.32 : 1,200.39 = 649.86 : x
  2. Step 2: Convert to fraction form
    871.32/1,200.39 = 649.86/x
  3. Step 3: Cross multiply
    871.32x = 1,200.39 × 649.86
  4. Step 4: Simplify right side
    871.32x = 780,085.45
  5. Step 5: Solve for x
    x = 780,085.45/871.32
  6. Step 6: Final answer
    x = 895.29

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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.