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Finding the Fourth Proportional to 399.36, 549.80 and 378.84

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Solution

The fourth proportional to 399.36, 549.80 and 378.84 is: 521.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.36 : 549.80 = 378.84 : x
  2. Step 2: Convert to fraction form
    399.36/549.80 = 378.84/x
  3. Step 3: Cross multiply
    399.36x = 549.80 × 378.84
  4. Step 4: Simplify right side
    399.36x = 208,286.23
  5. Step 5: Solve for x
    x = 208,286.23/399.36
  6. Step 6: Final answer
    x = 521.55

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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.