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Finding the Fourth Proportional to 401.50, 554.21 and 285.40

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Solution

The fourth proportional to 401.50, 554.21 and 285.40 is: 393.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    401.50 : 554.21 = 285.40 : x
  2. Step 2: Convert to fraction form
    401.50/554.21 = 285.40/x
  3. Step 3: Cross multiply
    401.50x = 554.21 × 285.40
  4. Step 4: Simplify right side
    401.50x = 158,171.53
  5. Step 5: Solve for x
    x = 158,171.53/401.50
  6. Step 6: Final answer
    x = 393.95

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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.