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Finding the Fourth Proportional to 378.46, 521.76 and 290

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Solution

The fourth proportional to 378.46, 521.76 and 290 is: 399.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.46 : 521.76 = 290 : x
  2. Step 2: Convert to fraction form
    378.46/521.76 = 290/x
  3. Step 3: Cross multiply
    378.46x = 521.76 × 290
  4. Step 4: Simplify right side
    378.46x = 151,310.40
  5. Step 5: Solve for x
    x = 151,310.40/378.46
  6. Step 6: Final answer
    x = 399.81

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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.