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Finding the Fourth Proportional to 491.42, 678.22 and 281.64

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Solution

The fourth proportional to 491.42, 678.22 and 281.64 is: 388.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.42 : 678.22 = 281.64 : x
  2. Step 2: Convert to fraction form
    491.42/678.22 = 281.64/x
  3. Step 3: Cross multiply
    491.42x = 678.22 × 281.64
  4. Step 4: Simplify right side
    491.42x = 191,013.18
  5. Step 5: Solve for x
    x = 191,013.18/491.42
  6. Step 6: Final answer
    x = 388.69

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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.