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Finding the Third Proportional to 642.30 and 842.91

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Solution

The third proportional to 642.30 and 842.91 is: 1,106.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.30 : 842.91 = 842.91 : x
  2. Step 2: Convert to fraction form
    642.30/842.91 = 842.91/x
  3. Step 3: Cross multiply
    642.30x = 842.91 × 842.91
  4. Step 4: Simplify right side
    642.30x = 710,490.95
  5. Step 5: Solve for x
    x = 710,490.95/642.30
  6. Step 6: Final answer
    x = 1,106.16

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Why These Related Problems?

These problems maintain the same ratio (1.31) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.