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Finding the Fourth Proportional to 47.42, 70.78 and 40.20

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Solution

The fourth proportional to 47.42, 70.78 and 40.20 is: 60.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.42 : 70.78 = 40.20 : x
  2. Step 2: Convert to fraction form
    47.42/70.78 = 40.20/x
  3. Step 3: Cross multiply
    47.42x = 70.78 × 40.20
  4. Step 4: Simplify right side
    47.42x = 2,845.36
  5. Step 5: Solve for x
    x = 2,845.36/47.42
  6. Step 6: Final answer
    x = 60.00

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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.