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Finding the Fourth Proportional to 313.50, 470.25 and 85.50

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Solution

The fourth proportional to 313.50, 470.25 and 85.50 is: 128.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    313.50 : 470.25 = 85.50 : x
  2. Step 2: Convert to fraction form
    313.50/470.25 = 85.50/x
  3. Step 3: Cross multiply
    313.50x = 470.25 × 85.50
  4. Step 4: Simplify right side
    313.50x = 40,206.38
  5. Step 5: Solve for x
    x = 40,206.38/313.50
  6. Step 6: Final answer
    x = 128.25

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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.