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Finding the Fourth Proportional to 49.80, 74.31 and 45

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Solution

The fourth proportional to 49.80, 74.31 and 45 is: 67.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    49.80 : 74.31 = 45 : x
  2. Step 2: Convert to fraction form
    49.80/74.31 = 45/x
  3. Step 3: Cross multiply
    49.80x = 74.31 × 45
  4. Step 4: Simplify right side
    49.80x = 3,343.95
  5. Step 5: Solve for x
    x = 3,343.95/49.80
  6. Step 6: Final answer
    x = 67.15

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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.