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Finding the Fourth Proportional to 1,139.88, 1,710 and 490.80

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Solution

The fourth proportional to 1,139.88, 1,710 and 490.80 is: 736.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,139.88 : 1,710 = 490.80 : x
  2. Step 2: Convert to fraction form
    1,139.88/1,710 = 490.80/x
  3. Step 3: Cross multiply
    1,139.88x = 1,710 × 490.80
  4. Step 4: Simplify right side
    1,139.88x = 839,268
  5. Step 5: Solve for x
    x = 839,268/1,139.88
  6. Step 6: Final answer
    x = 736.28

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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.