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Finding the Fourth Proportional to 1,256.37, 1,886.28 and 640.49

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Solution

The fourth proportional to 1,256.37, 1,886.28 and 640.49 is: 961.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,256.37 : 1,886.28 = 640.49 : x
  2. Step 2: Convert to fraction form
    1,256.37/1,886.28 = 640.49/x
  3. Step 3: Cross multiply
    1,256.37x = 1,886.28 × 640.49
  4. Step 4: Simplify right side
    1,256.37x = 1,208,143.48
  5. Step 5: Solve for x
    x = 1,208,143.48/1,256.37
  6. Step 6: Final answer
    x = 961.61

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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.