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Finding the Fourth Proportional to 427.04, 639.90 and 389.10

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Solution

The fourth proportional to 427.04, 639.90 and 389.10 is: 583.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.04 : 639.90 = 389.10 : x
  2. Step 2: Convert to fraction form
    427.04/639.90 = 389.10/x
  3. Step 3: Cross multiply
    427.04x = 639.90 × 389.10
  4. Step 4: Simplify right side
    427.04x = 248,987.49
  5. Step 5: Solve for x
    x = 248,987.49/427.04
  6. Step 6: Final answer
    x = 583.06

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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.