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Finding the Fourth Proportional to 378.80, 521.16 and 357.20

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Solution

The fourth proportional to 378.80, 521.16 and 357.20 is: 491.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.80 : 521.16 = 357.20 : x
  2. Step 2: Convert to fraction form
    378.80/521.16 = 357.20/x
  3. Step 3: Cross multiply
    378.80x = 521.16 × 357.20
  4. Step 4: Simplify right side
    378.80x = 186,158.35
  5. Step 5: Solve for x
    x = 186,158.35/378.80
  6. Step 6: Final answer
    x = 491.44

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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.