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Finding the Fourth Proportional to 928.75, 1,393.28 and 380.79

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Solution

The fourth proportional to 928.75, 1,393.28 and 380.79 is: 571.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.75 : 1,393.28 = 380.79 : x
  2. Step 2: Convert to fraction form
    928.75/1,393.28 = 380.79/x
  3. Step 3: Cross multiply
    928.75x = 1,393.28 × 380.79
  4. Step 4: Simplify right side
    928.75x = 530,547.09
  5. Step 5: Solve for x
    x = 530,547.09/928.75
  6. Step 6: Final answer
    x = 571.25

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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.