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Finding the Fourth Proportional to 486.25, 670.69 and 311.51

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Solution

The fourth proportional to 486.25, 670.69 and 311.51 is: 429.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.25 : 670.69 = 311.51 : x
  2. Step 2: Convert to fraction form
    486.25/670.69 = 311.51/x
  3. Step 3: Cross multiply
    486.25x = 670.69 × 311.51
  4. Step 4: Simplify right side
    486.25x = 208,927.54
  5. Step 5: Solve for x
    x = 208,927.54/486.25
  6. Step 6: Final answer
    x = 429.67

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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.