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Finding the Fourth Proportional to 30.77, 45.85 and 30.21

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Solution

The fourth proportional to 30.77, 45.85 and 30.21 is: 45.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.77 : 45.85 = 30.21 : x
  2. Step 2: Convert to fraction form
    30.77/45.85 = 30.21/x
  3. Step 3: Cross multiply
    30.77x = 45.85 × 30.21
  4. Step 4: Simplify right side
    30.77x = 1,385.17
  5. Step 5: Solve for x
    x = 1,385.17/30.77
  6. Step 6: Final answer
    x = 45.02

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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.