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Finding the Fourth Proportional to 1,871.78, 2,807.26 and 639.18

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Solution

The fourth proportional to 1,871.78, 2,807.26 and 639.18 is: 958.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,871.78 : 2,807.26 = 639.18 : x
  2. Step 2: Convert to fraction form
    1,871.78/2,807.26 = 639.18/x
  3. Step 3: Cross multiply
    1,871.78x = 2,807.26 × 639.18
  4. Step 4: Simplify right side
    1,871.78x = 1,794,344.45
  5. Step 5: Solve for x
    x = 1,794,344.45/1,871.78
  6. Step 6: Final answer
    x = 958.63

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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.