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Finding the Fourth Proportional to 317.61, 435.87 and 312.21

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Solution

The fourth proportional to 317.61, 435.87 and 312.21 is: 428.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    317.61 : 435.87 = 312.21 : x
  2. Step 2: Convert to fraction form
    317.61/435.87 = 312.21/x
  3. Step 3: Cross multiply
    317.61x = 435.87 × 312.21
  4. Step 4: Simplify right side
    317.61x = 136,082.97
  5. Step 5: Solve for x
    x = 136,082.97/317.61
  6. Step 6: Final answer
    x = 428.46

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.