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Finding the Fourth Proportional to 258.99, 388.71 and 105

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Solution

The fourth proportional to 258.99, 388.71 and 105 is: 157.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.99 : 388.71 = 105 : x
  2. Step 2: Convert to fraction form
    258.99/388.71 = 105/x
  3. Step 3: Cross multiply
    258.99x = 388.71 × 105
  4. Step 4: Simplify right side
    258.99x = 40,814.55
  5. Step 5: Solve for x
    x = 40,814.55/258.99
  6. Step 6: Final answer
    x = 157.59

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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.