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Finding the Fourth Proportional to 728.55, 1,005.42 and 413.80

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Solution

The fourth proportional to 728.55, 1,005.42 and 413.80 is: 571.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.55 : 1,005.42 = 413.80 : x
  2. Step 2: Convert to fraction form
    728.55/1,005.42 = 413.80/x
  3. Step 3: Cross multiply
    728.55x = 1,005.42 × 413.80
  4. Step 4: Simplify right side
    728.55x = 416,045.31
  5. Step 5: Solve for x
    x = 416,045.31/728.55
  6. Step 6: Final answer
    x = 571.06

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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.