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Finding the Fourth Proportional to 622.30, 858.78 and 398

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Solution

The fourth proportional to 622.30, 858.78 and 398 is: 549.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    622.30 : 858.78 = 398 : x
  2. Step 2: Convert to fraction form
    622.30/858.78 = 398/x
  3. Step 3: Cross multiply
    622.30x = 858.78 × 398
  4. Step 4: Simplify right side
    622.30x = 341,794.44
  5. Step 5: Solve for x
    x = 341,794.44/622.30
  6. Step 6: Final answer
    x = 549.24

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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.