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Finding the Fourth Proportional to 1,238.80, 1,858.20 and 361.30

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Solution

The fourth proportional to 1,238.80, 1,858.20 and 361.30 is: 541.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,238.80 : 1,858.20 = 361.30 : x
  2. Step 2: Convert to fraction form
    1,238.80/1,858.20 = 361.30/x
  3. Step 3: Cross multiply
    1,238.80x = 1,858.20 × 361.30
  4. Step 4: Simplify right side
    1,238.80x = 671,367.66
  5. Step 5: Solve for x
    x = 671,367.66/1,238.80
  6. Step 6: Final answer
    x = 541.95

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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.