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Finding the Fourth Proportional to 765.05, 1,055.70 and 485.33

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Solution

The fourth proportional to 765.05, 1,055.70 and 485.33 is: 669.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.05 : 1,055.70 = 485.33 : x
  2. Step 2: Convert to fraction form
    765.05/1,055.70 = 485.33/x
  3. Step 3: Cross multiply
    765.05x = 1,055.70 × 485.33
  4. Step 4: Simplify right side
    765.05x = 512,357.60
  5. Step 5: Solve for x
    x = 512,357.60/765.05
  6. Step 6: Final answer
    x = 669.71

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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.