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Finding the Fourth Proportional to 645.26, 890.34 and 448.70

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Solution

The fourth proportional to 645.26, 890.34 and 448.70 is: 619.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.26 : 890.34 = 448.70 : x
  2. Step 2: Convert to fraction form
    645.26/890.34 = 448.70/x
  3. Step 3: Cross multiply
    645.26x = 890.34 × 448.70
  4. Step 4: Simplify right side
    645.26x = 399,495.56
  5. Step 5: Solve for x
    x = 399,495.56/645.26
  6. Step 6: Final answer
    x = 619.12

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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.