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Finding the Fourth Proportional to 386.98, 579.93 and 257.05

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Solution

The fourth proportional to 386.98, 579.93 and 257.05 is: 385.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.98 : 579.93 = 257.05 : x
  2. Step 2: Convert to fraction form
    386.98/579.93 = 257.05/x
  3. Step 3: Cross multiply
    386.98x = 579.93 × 257.05
  4. Step 4: Simplify right side
    386.98x = 149,071.01
  5. Step 5: Solve for x
    x = 149,071.01/386.98
  6. Step 6: Final answer
    x = 385.22

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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.