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Finding the Fourth Proportional to 928.30, 1,278.30 and 665.86

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Solution

The fourth proportional to 928.30, 1,278.30 and 665.86 is: 916.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.30 : 1,278.30 = 665.86 : x
  2. Step 2: Convert to fraction form
    928.30/1,278.30 = 665.86/x
  3. Step 3: Cross multiply
    928.30x = 1,278.30 × 665.86
  4. Step 4: Simplify right side
    928.30x = 851,168.84
  5. Step 5: Solve for x
    x = 851,168.84/928.30
  6. Step 6: Final answer
    x = 916.91

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1.5x scale

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.