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Finding the Fourth Proportional to 759.71, 1,139.72 and 430.80

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Solution

The fourth proportional to 759.71, 1,139.72 and 430.80 is: 646.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    759.71 : 1,139.72 = 430.80 : x
  2. Step 2: Convert to fraction form
    759.71/1,139.72 = 430.80/x
  3. Step 3: Cross multiply
    759.71x = 1,139.72 × 430.80
  4. Step 4: Simplify right side
    759.71x = 490,992.45
  5. Step 5: Solve for x
    x = 490,992.45/759.71
  6. Step 6: Final answer
    x = 646.29

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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.