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Finding the Fourth Proportional to 858.34, 1,287.87 and 413.38

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Solution

The fourth proportional to 858.34, 1,287.87 and 413.38 is: 620.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.34 : 1,287.87 = 413.38 : x
  2. Step 2: Convert to fraction form
    858.34/1,287.87 = 413.38/x
  3. Step 3: Cross multiply
    858.34x = 1,287.87 × 413.38
  4. Step 4: Simplify right side
    858.34x = 532,379.76
  5. Step 5: Solve for x
    x = 532,379.76/858.34
  6. Step 6: Final answer
    x = 620.24

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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.