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Finding the Fourth Proportional to 528.80, 791.40 and 485.60

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Solution

The fourth proportional to 528.80, 791.40 and 485.60 is: 726.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    528.80 : 791.40 = 485.60 : x
  2. Step 2: Convert to fraction form
    528.80/791.40 = 485.60/x
  3. Step 3: Cross multiply
    528.80x = 791.40 × 485.60
  4. Step 4: Simplify right side
    528.80x = 384,303.84
  5. Step 5: Solve for x
    x = 384,303.84/528.80
  6. Step 6: Final answer
    x = 726.75

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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.