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Finding the Fourth Proportional to 261.08, 388.78 and 258.21

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Solution

The fourth proportional to 261.08, 388.78 and 258.21 is: 384.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.08 : 388.78 = 258.21 : x
  2. Step 2: Convert to fraction form
    261.08/388.78 = 258.21/x
  3. Step 3: Cross multiply
    261.08x = 388.78 × 258.21
  4. Step 4: Simplify right side
    261.08x = 100,386.88
  5. Step 5: Solve for x
    x = 100,386.88/261.08
  6. Step 6: Final answer
    x = 384.51

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.