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Finding the Fourth Proportional to 386.51, 579.40 and 256.55

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Solution

The fourth proportional to 386.51, 579.40 and 256.55 is: 384.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.51 : 579.40 = 256.55 : x
  2. Step 2: Convert to fraction form
    386.51/579.40 = 256.55/x
  3. Step 3: Cross multiply
    386.51x = 579.40 × 256.55
  4. Step 4: Simplify right side
    386.51x = 148,645.07
  5. Step 5: Solve for x
    x = 148,645.07/386.51
  6. Step 6: Final answer
    x = 384.58

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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.