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Finding the Fourth Proportional to 378.75, 522.75 and 221.42

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Solution

The fourth proportional to 378.75, 522.75 and 221.42 is: 305.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.75 : 522.75 = 221.42 : x
  2. Step 2: Convert to fraction form
    378.75/522.75 = 221.42/x
  3. Step 3: Cross multiply
    378.75x = 522.75 × 221.42
  4. Step 4: Simplify right side
    378.75x = 115,747.31
  5. Step 5: Solve for x
    x = 115,747.31/378.75
  6. Step 6: Final answer
    x = 305.60

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Find fourth proportional to 189.38, 261.38 and 110.71
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Double scale
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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.