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Finding the Fourth Proportional to 319.16, 478.28 and 145.40

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Solution

The fourth proportional to 319.16, 478.28 and 145.40 is: 217.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.16 : 478.28 = 145.40 : x
  2. Step 2: Convert to fraction form
    319.16/478.28 = 145.40/x
  3. Step 3: Cross multiply
    319.16x = 478.28 × 145.40
  4. Step 4: Simplify right side
    319.16x = 69,539.88
  5. Step 5: Solve for x
    x = 69,539.88/319.16
  6. Step 6: Final answer
    x = 217.89

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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.