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Finding the Fourth Proportional to 405.42, 607.78 and 199.89

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Solution

The fourth proportional to 405.42, 607.78 and 199.89 is: 299.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.42 : 607.78 = 199.89 : x
  2. Step 2: Convert to fraction form
    405.42/607.78 = 199.89/x
  3. Step 3: Cross multiply
    405.42x = 607.78 × 199.89
  4. Step 4: Simplify right side
    405.42x = 121,489.14
  5. Step 5: Solve for x
    x = 121,489.14/405.42
  6. Step 6: Final answer
    x = 299.66

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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.