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Finding the Fourth Proportional to 765.27, 1,055.79 and 485.42

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Solution

The fourth proportional to 765.27, 1,055.79 and 485.42 is: 669.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.27 : 1,055.79 = 485.42 : x
  2. Step 2: Convert to fraction form
    765.27/1,055.79 = 485.42/x
  3. Step 3: Cross multiply
    765.27x = 1,055.79 × 485.42
  4. Step 4: Simplify right side
    765.27x = 512,496.30
  5. Step 5: Solve for x
    x = 512,496.30/765.27
  6. Step 6: Final answer
    x = 669.69

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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.