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Finding the Fourth Proportional to 928.40, 1,392.60 and 380.19

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Solution

The fourth proportional to 928.40, 1,392.60 and 380.19 is: 570.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.40 : 1,392.60 = 380.19 : x
  2. Step 2: Convert to fraction form
    928.40/1,392.60 = 380.19/x
  3. Step 3: Cross multiply
    928.40x = 1,392.60 × 380.19
  4. Step 4: Simplify right side
    928.40x = 529,452.59
  5. Step 5: Solve for x
    x = 529,452.59/928.40
  6. Step 6: Final answer
    x = 570.29

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Double scale
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Similar ratio
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1.5x scale

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.