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Finding the Fourth Proportional to 645.40, 890.95 and 622.31

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Solution

The fourth proportional to 645.40, 890.95 and 622.31 is: 859.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.40 : 890.95 = 622.31 : x
  2. Step 2: Convert to fraction form
    645.40/890.95 = 622.31/x
  3. Step 3: Cross multiply
    645.40x = 890.95 × 622.31
  4. Step 4: Simplify right side
    645.40x = 554,447.09
  5. Step 5: Solve for x
    x = 554,447.09/645.40
  6. Step 6: Final answer
    x = 859.08

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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.