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Finding the Fourth Proportional to 380.79, 570.78 and 258.75

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Solution

The fourth proportional to 380.79, 570.78 and 258.75 is: 387.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    380.79 : 570.78 = 258.75 : x
  2. Step 2: Convert to fraction form
    380.79/570.78 = 258.75/x
  3. Step 3: Cross multiply
    380.79x = 570.78 × 258.75
  4. Step 4: Simplify right side
    380.79x = 147,689.33
  5. Step 5: Solve for x
    x = 147,689.33/380.79
  6. Step 6: Final answer
    x = 387.85

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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.