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Finding the Fourth Proportional to 776.25, 1,169.70 and 642.30

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Solution

The fourth proportional to 776.25, 1,169.70 and 642.30 is: 967.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    776.25 : 1,169.70 = 642.30 : x
  2. Step 2: Convert to fraction form
    776.25/1,169.70 = 642.30/x
  3. Step 3: Cross multiply
    776.25x = 1,169.70 × 642.30
  4. Step 4: Simplify right side
    776.25x = 751,298.31
  5. Step 5: Solve for x
    x = 751,298.31/776.25
  6. Step 6: Final answer
    x = 967.86

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.