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Finding the Fourth Proportional to 971.07, 1,340.05 and 639.67

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Solution

The fourth proportional to 971.07, 1,340.05 and 639.67 is: 882.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    971.07 : 1,340.05 = 639.67 : x
  2. Step 2: Convert to fraction form
    971.07/1,340.05 = 639.67/x
  3. Step 3: Cross multiply
    971.07x = 1,340.05 × 639.67
  4. Step 4: Simplify right side
    971.07x = 857,189.78
  5. Step 5: Solve for x
    x = 857,189.78/971.07
  6. Step 6: Final answer
    x = 882.73

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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.