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Finding the Fourth Proportional to 830, 1,245 and 317.12

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Solution

The fourth proportional to 830, 1,245 and 317.12 is: 475.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    830 : 1,245 = 317.12 : x
  2. Step 2: Convert to fraction form
    830/1,245 = 317.12/x
  3. Step 3: Cross multiply
    830x = 1,245 × 317.12
  4. Step 4: Simplify right side
    830x = 394,814.40
  5. Step 5: Solve for x
    x = 394,814.40/830
  6. Step 6: Final answer
    x = 475.68

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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.