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Finding the Fourth Proportional to 772.80, 1,159.20 and 689.10

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Solution

The fourth proportional to 772.80, 1,159.20 and 689.10 is: 1,033.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    772.80 : 1,159.20 = 689.10 : x
  2. Step 2: Convert to fraction form
    772.80/1,159.20 = 689.10/x
  3. Step 3: Cross multiply
    772.80x = 1,159.20 × 689.10
  4. Step 4: Simplify right side
    772.80x = 798,804.72
  5. Step 5: Solve for x
    x = 798,804.72/772.80
  6. Step 6: Final answer
    x = 1,033.65

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Similar ratio
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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.