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Finding the Fourth Proportional to 645.02, 891.23 and 505.43

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Solution

The fourth proportional to 645.02, 891.23 and 505.43 is: 698.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.02 : 891.23 = 505.43 : x
  2. Step 2: Convert to fraction form
    645.02/891.23 = 505.43/x
  3. Step 3: Cross multiply
    645.02x = 891.23 × 505.43
  4. Step 4: Simplify right side
    645.02x = 450,447.40
  5. Step 5: Solve for x
    x = 450,447.40/645.02
  6. Step 6: Final answer
    x = 698.35

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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.