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Finding the Fourth Proportional to 613.06, 921.30 and 421.90

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Solution

The fourth proportional to 613.06, 921.30 and 421.90 is: 634.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    613.06 : 921.30 = 421.90 : x
  2. Step 2: Convert to fraction form
    613.06/921.30 = 421.90/x
  3. Step 3: Cross multiply
    613.06x = 921.30 × 421.90
  4. Step 4: Simplify right side
    613.06x = 388,696.47
  5. Step 5: Solve for x
    x = 388,696.47/613.06
  6. Step 6: Final answer
    x = 634.03

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.