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Finding the Fourth Proportional to 386.65, 579.94 and 143.21

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Solution

The fourth proportional to 386.65, 579.94 and 143.21 is: 214.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.65 : 579.94 = 143.21 : x
  2. Step 2: Convert to fraction form
    386.65/579.94 = 143.21/x
  3. Step 3: Cross multiply
    386.65x = 579.94 × 143.21
  4. Step 4: Simplify right side
    386.65x = 83,053.21
  5. Step 5: Solve for x
    x = 83,053.21/386.65
  6. Step 6: Final answer
    x = 214.80

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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.