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Finding the Fourth Proportional to 779.64, 1,167.38 and 643.28

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Solution

The fourth proportional to 779.64, 1,167.38 and 643.28 is: 963.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    779.64 : 1,167.38 = 643.28 : x
  2. Step 2: Convert to fraction form
    779.64/1,167.38 = 643.28/x
  3. Step 3: Cross multiply
    779.64x = 1,167.38 × 643.28
  4. Step 4: Simplify right side
    779.64x = 750,952.21
  5. Step 5: Solve for x
    x = 750,952.21/779.64
  6. Step 6: Final answer
    x = 963.20

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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.