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Finding the Fourth Proportional to 782.36, 1,078.62 and 649.69

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Solution

The fourth proportional to 782.36, 1,078.62 and 649.69 is: 895.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.36 : 1,078.62 = 649.69 : x
  2. Step 2: Convert to fraction form
    782.36/1,078.62 = 649.69/x
  3. Step 3: Cross multiply
    782.36x = 1,078.62 × 649.69
  4. Step 4: Simplify right side
    782.36x = 700,768.63
  5. Step 5: Solve for x
    x = 700,768.63/782.36
  6. Step 6: Final answer
    x = 895.72

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.