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Finding the Fourth Proportional to 622.38, 858.69 and 386.40

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Solution

The fourth proportional to 622.38, 858.69 and 386.40 is: 533.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    622.38 : 858.69 = 386.40 : x
  2. Step 2: Convert to fraction form
    622.38/858.69 = 386.40/x
  3. Step 3: Cross multiply
    622.38x = 858.69 × 386.40
  4. Step 4: Simplify right side
    622.38x = 331,797.82
  5. Step 5: Solve for x
    x = 331,797.82/622.38
  6. Step 6: Final answer
    x = 533.11

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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.