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Finding the Fourth Proportional to 1,139.64, 1,707.80 and 619.20

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Solution

The fourth proportional to 1,139.64, 1,707.80 and 619.20 is: 927.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,139.64 : 1,707.80 = 619.20 : x
  2. Step 2: Convert to fraction form
    1,139.64/1,707.80 = 619.20/x
  3. Step 3: Cross multiply
    1,139.64x = 1,707.80 × 619.20
  4. Step 4: Simplify right side
    1,139.64x = 1,057,462.77
  5. Step 5: Solve for x
    x = 1,057,462.77/1,139.64
  6. Step 6: Final answer
    x = 927.90

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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.