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Finding the Fourth Proportional to 491.85, 678.81 and 282.09

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Solution

The fourth proportional to 491.85, 678.81 and 282.09 is: 389.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.85 : 678.81 = 282.09 : x
  2. Step 2: Convert to fraction form
    491.85/678.81 = 282.09/x
  3. Step 3: Cross multiply
    491.85x = 678.81 × 282.09
  4. Step 4: Simplify right side
    491.85x = 191,485.51
  5. Step 5: Solve for x
    x = 191,485.51/491.85
  6. Step 6: Final answer
    x = 389.32

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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.