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Finding the Fourth Proportional to 928.60, 1,391.80 and 380.64

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Solution

The fourth proportional to 928.60, 1,391.80 and 380.64 is: 570.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.60 : 1,391.80 = 380.64 : x
  2. Step 2: Convert to fraction form
    928.60/1,391.80 = 380.64/x
  3. Step 3: Cross multiply
    928.60x = 1,391.80 × 380.64
  4. Step 4: Simplify right side
    928.60x = 529,774.75
  5. Step 5: Solve for x
    x = 529,774.75/928.60
  6. Step 6: Final answer
    x = 570.51

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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.