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Finding the Fourth Proportional to 620.66, 857.08 and 399.98

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Solution

The fourth proportional to 620.66, 857.08 and 399.98 is: 552.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.66 : 857.08 = 399.98 : x
  2. Step 2: Convert to fraction form
    620.66/857.08 = 399.98/x
  3. Step 3: Cross multiply
    620.66x = 857.08 × 399.98
  4. Step 4: Simplify right side
    620.66x = 342,814.86
  5. Step 5: Solve for x
    x = 342,814.86/620.66
  6. Step 6: Final answer
    x = 552.34

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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.