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Finding the Fourth Proportional to 305.47, 421.57 and 286.77

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Solution

The fourth proportional to 305.47, 421.57 and 286.77 is: 395.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.47 : 421.57 = 286.77 : x
  2. Step 2: Convert to fraction form
    305.47/421.57 = 286.77/x
  3. Step 3: Cross multiply
    305.47x = 421.57 × 286.77
  4. Step 4: Simplify right side
    305.47x = 120,895.57
  5. Step 5: Solve for x
    x = 120,895.57/305.47
  6. Step 6: Final answer
    x = 395.77

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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.