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Finding the Fourth Proportional to 380.80, 570.12 and 258.40

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Solution

The fourth proportional to 380.80, 570.12 and 258.40 is: 386.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    380.80 : 570.12 = 258.40 : x
  2. Step 2: Convert to fraction form
    380.80/570.12 = 258.40/x
  3. Step 3: Cross multiply
    380.80x = 570.12 × 258.40
  4. Step 4: Simplify right side
    380.80x = 147,319.01
  5. Step 5: Solve for x
    x = 147,319.01/380.80
  6. Step 6: Final answer
    x = 386.87

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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.