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Finding the Fourth Proportional to 645.60, 889.92 and 448.80

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Solution

The fourth proportional to 645.60, 889.92 and 448.80 is: 618.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.60 : 889.92 = 448.80 : x
  2. Step 2: Convert to fraction form
    645.60/889.92 = 448.80/x
  3. Step 3: Cross multiply
    645.60x = 889.92 × 448.80
  4. Step 4: Simplify right side
    645.60x = 399,396.10
  5. Step 5: Solve for x
    x = 399,396.10/645.60
  6. Step 6: Final answer
    x = 618.64

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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.