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Finding the Fourth Proportional to 777.38, 1,171.41 and 643.43

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Solution

The fourth proportional to 777.38, 1,171.41 and 643.43 is: 969.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    777.38 : 1,171.41 = 643.43 : x
  2. Step 2: Convert to fraction form
    777.38/1,171.41 = 643.43/x
  3. Step 3: Cross multiply
    777.38x = 1,171.41 × 643.43
  4. Step 4: Simplify right side
    777.38x = 753,714.48
  5. Step 5: Solve for x
    x = 753,714.48/777.38
  6. Step 6: Final answer
    x = 969.56

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1.5x scale

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.