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Finding the Fourth Proportional to 771.31, 1,156.15 and 385.75

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Solution

The fourth proportional to 771.31, 1,156.15 and 385.75 is: 578.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    771.31 : 1,156.15 = 385.75 : x
  2. Step 2: Convert to fraction form
    771.31/1,156.15 = 385.75/x
  3. Step 3: Cross multiply
    771.31x = 1,156.15 × 385.75
  4. Step 4: Simplify right side
    771.31x = 445,984.86
  5. Step 5: Solve for x
    x = 445,984.86/771.31
  6. Step 6: Final answer
    x = 578.22

Related Problems

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Half scale
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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.