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Finding the Fourth Proportional to 620.95, 857.16 and 399.91

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Solution

The fourth proportional to 620.95, 857.16 and 399.91 is: 552.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.95 : 857.16 = 399.91 : x
  2. Step 2: Convert to fraction form
    620.95/857.16 = 399.91/x
  3. Step 3: Cross multiply
    620.95x = 857.16 × 399.91
  4. Step 4: Simplify right side
    620.95x = 342,786.86
  5. Step 5: Solve for x
    x = 342,786.86/620.95
  6. Step 6: Final answer
    x = 552.04

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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.