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Finding the Fourth Proportional to 830.66, 1,145.48 and 643.82

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Solution

The fourth proportional to 830.66, 1,145.48 and 643.82 is: 887.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.66 : 1,145.48 = 643.82 : x
  2. Step 2: Convert to fraction form
    830.66/1,145.48 = 643.82/x
  3. Step 3: Cross multiply
    830.66x = 1,145.48 × 643.82
  4. Step 4: Simplify right side
    830.66x = 737,473.99
  5. Step 5: Solve for x
    x = 737,473.99/830.66
  6. Step 6: Final answer
    x = 887.82

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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.