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Finding the Fourth Proportional to 380.40, 570.15 and 145.95

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Solution

The fourth proportional to 380.40, 570.15 and 145.95 is: 218.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    380.40 : 570.15 = 145.95 : x
  2. Step 2: Convert to fraction form
    380.40/570.15 = 145.95/x
  3. Step 3: Cross multiply
    380.40x = 570.15 × 145.95
  4. Step 4: Simplify right side
    380.40x = 83,213.39
  5. Step 5: Solve for x
    x = 83,213.39/380.40
  6. Step 6: Final answer
    x = 218.75

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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.