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Finding the Fourth Proportional to 491.71, 678.62 and 281.90

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Solution

The fourth proportional to 491.71, 678.62 and 281.90 is: 389.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.71 : 678.62 = 281.90 : x
  2. Step 2: Convert to fraction form
    491.71/678.62 = 281.90/x
  3. Step 3: Cross multiply
    491.71x = 678.62 × 281.90
  4. Step 4: Simplify right side
    491.71x = 191,304.67
  5. Step 5: Solve for x
    x = 191,304.67/491.71
  6. Step 6: Final answer
    x = 389.06

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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.