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Finding the Fourth Proportional to 620.13, 855.57 and 421.23

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Solution

The fourth proportional to 620.13, 855.57 and 421.23 is: 581.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.13 : 855.57 = 421.23 : x
  2. Step 2: Convert to fraction form
    620.13/855.57 = 421.23/x
  3. Step 3: Cross multiply
    620.13x = 855.57 × 421.23
  4. Step 4: Simplify right side
    620.13x = 360,391.75
  5. Step 5: Solve for x
    x = 360,391.75/620.13
  6. Step 6: Final answer
    x = 581.16

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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.