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Finding the Fourth Proportional to 860.81, 1,291.16 and 275.78

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Solution

The fourth proportional to 860.81, 1,291.16 and 275.78 is: 413.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.81 : 1,291.16 = 275.78 : x
  2. Step 2: Convert to fraction form
    860.81/1,291.16 = 275.78/x
  3. Step 3: Cross multiply
    860.81x = 1,291.16 × 275.78
  4. Step 4: Simplify right side
    860.81x = 356,068.27
  5. Step 5: Solve for x
    x = 356,068.27/860.81
  6. Step 6: Final answer
    x = 413.65

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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.