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Finding the Fourth Proportional to 261.04, 390.78 and 217.30

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Solution

The fourth proportional to 261.04, 390.78 and 217.30 is: 325.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.04 : 390.78 = 217.30 : x
  2. Step 2: Convert to fraction form
    261.04/390.78 = 217.30/x
  3. Step 3: Cross multiply
    261.04x = 390.78 × 217.30
  4. Step 4: Simplify right side
    261.04x = 84,916.49
  5. Step 5: Solve for x
    x = 84,916.49/261.04
  6. Step 6: Final answer
    x = 325.30

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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.