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Finding the Fourth Proportional to 928.86, 1,391.85 and 380.58

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Solution

The fourth proportional to 928.86, 1,391.85 and 380.58 is: 570.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.86 : 1,391.85 = 380.58 : x
  2. Step 2: Convert to fraction form
    928.86/1,391.85 = 380.58/x
  3. Step 3: Cross multiply
    928.86x = 1,391.85 × 380.58
  4. Step 4: Simplify right side
    928.86x = 529,710.27
  5. Step 5: Solve for x
    x = 529,710.27/928.86
  6. Step 6: Final answer
    x = 570.28

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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.