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Finding the Fourth Proportional to 830.70, 1,145.42 and 620.21

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Solution

The fourth proportional to 830.70, 1,145.42 and 620.21 is: 855.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.70 : 1,145.42 = 620.21 : x
  2. Step 2: Convert to fraction form
    830.70/1,145.42 = 620.21/x
  3. Step 3: Cross multiply
    830.70x = 1,145.42 × 620.21
  4. Step 4: Simplify right side
    830.70x = 710,392.11
  5. Step 5: Solve for x
    x = 710,392.11/830.70
  6. Step 6: Final answer
    x = 855.17

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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.