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Finding the Fourth Proportional to 47.00, 64.80 and 30.60

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Solution

The fourth proportional to 47.00, 64.80 and 30.60 is: 42.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.00 : 64.80 = 30.60 : x
  2. Step 2: Convert to fraction form
    47.00/64.80 = 30.60/x
  3. Step 3: Cross multiply
    47.00x = 64.80 × 30.60
  4. Step 4: Simplify right side
    47.00x = 1,982.88
  5. Step 5: Solve for x
    x = 1,982.88/47.00
  6. Step 6: Final answer
    x = 42.19

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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.