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Finding the Fourth Proportional to 971.37, 1,339.88 and 640.22

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Solution

The fourth proportional to 971.37, 1,339.88 and 640.22 is: 883.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    971.37 : 1,339.88 = 640.22 : x
  2. Step 2: Convert to fraction form
    971.37/1,339.88 = 640.22/x
  3. Step 3: Cross multiply
    971.37x = 1,339.88 × 640.22
  4. Step 4: Simplify right side
    971.37x = 857,808.07
  5. Step 5: Solve for x
    x = 857,808.07/971.37
  6. Step 6: Final answer
    x = 883.09

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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.