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Finding the Fourth Proportional to 491.37, 678.21 and 281.67

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Solution

The fourth proportional to 491.37, 678.21 and 281.67 is: 388.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.37 : 678.21 = 281.67 : x
  2. Step 2: Convert to fraction form
    491.37/678.21 = 281.67/x
  3. Step 3: Cross multiply
    491.37x = 678.21 × 281.67
  4. Step 4: Simplify right side
    491.37x = 191,030.35
  5. Step 5: Solve for x
    x = 191,030.35/491.37
  6. Step 6: Final answer
    x = 388.77

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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.