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Finding the Fourth Proportional to 311.78, 430.23 and 180.77

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Solution

The fourth proportional to 311.78, 430.23 and 180.77 is: 249.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.78 : 430.23 = 180.77 : x
  2. Step 2: Convert to fraction form
    311.78/430.23 = 180.77/x
  3. Step 3: Cross multiply
    311.78x = 430.23 × 180.77
  4. Step 4: Simplify right side
    311.78x = 77,770.53
  5. Step 5: Solve for x
    x = 77,770.53/311.78
  6. Step 6: Final answer
    x = 249.44

Related Problems

Find fourth proportional to 155.89, 215.12 and 90.38
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Double scale
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1.5x scale

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.