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Finding the Fourth Proportional to 718.80, 1,079.40 and 389.52

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Solution

The fourth proportional to 718.80, 1,079.40 and 389.52 is: 584.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.80 : 1,079.40 = 389.52 : x
  2. Step 2: Convert to fraction form
    718.80/1,079.40 = 389.52/x
  3. Step 3: Cross multiply
    718.80x = 1,079.40 × 389.52
  4. Step 4: Simplify right side
    718.80x = 420,447.89
  5. Step 5: Solve for x
    x = 420,447.89/718.80
  6. Step 6: Final answer
    x = 584.93

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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.