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Finding the Fourth Proportional to 319, 478.50 and 91

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Solution

The fourth proportional to 319, 478.50 and 91 is: 136.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    319 : 478.50 = 91 : x
  2. Step 2: Convert to fraction form
    319/478.50 = 91/x
  3. Step 3: Cross multiply
    319x = 478.50 × 91
  4. Step 4: Simplify right side
    319x = 43,543.50
  5. Step 5: Solve for x
    x = 43,543.50/319
  6. Step 6: Final answer
    x = 136.50

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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.