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Finding the Fourth Proportional to 319.40, 478.72 and 145.82

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Solution

The fourth proportional to 319.40, 478.72 and 145.82 is: 218.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.40 : 478.72 = 145.82 : x
  2. Step 2: Convert to fraction form
    319.40/478.72 = 145.82/x
  3. Step 3: Cross multiply
    319.40x = 478.72 × 145.82
  4. Step 4: Simplify right side
    319.40x = 69,806.95
  5. Step 5: Solve for x
    x = 69,806.95/319.40
  6. Step 6: Final answer
    x = 218.56

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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.